BBC 632 - Complete Dart Short Block w/Flat Top Pistons - K1 crank/rods

4.600 Bore x 4.750 Stroke

4340 Manley Forged Crank

Manley 6.700 H-Beam Rods

Wiseco 2618 Aircraft Alloy Forged Flat Top Pistons

This short block kit is not assembled.

All parts are brand new, first-line, unblemished, and balanced. This short block kit is not assembled.

See our other listings for the assembled version of this short block.

Kit Includes:

• A brand new Generation Dart block, decked, bored, and honed to specs
• Coated cam bearings
• Manley crankshaft and 4340 Manley rods
• Wiseco forged pistons
• High-performance rings
• Clevite or King bearings
• Heavy-duty 168 or 153 tooth flexplate
• ATI Super damper

This assembly is fully balanced. See details for all actual specs. In the lower section of this ad is information on the various upgrades we offer in our other listings.

Custom Built to Your Specifications

Our short block kits are custom-built to your specifications, including piston configurations, compression ratio, and available upgrades.

BBC New Generation Dart Block

Bore: 10.200" Standard Deck Height

We now use the New Generation Dart blocks in our BBC 572 engine builds. The New Generation Dart block is a significant advancement in overall construction compared to other blocks on the market. Dimensional specs are spot on, which has been an issue with other blocks we have used in the past. Many top engine builders, including ourselves, have found the new Dart block to be superior to the earlier generation Big M series Dart block in many ways.

Included Components:

• SBC/BBC Chevy Oil Filter Adapter
• High-Performance Cam Bearings for Dart SHP Block
• Neither part is installed, it's included in extra parts bag

The block is bored to size with our new Centroid touch probe machine, ensuring precise accuracy. Few machine shops have access to a machine of this caliber.

We also deck the blocks to an RA finish of approximately 15 or better. This decking procedure is done using our Centroid DRX 750 CNC machine . Many brand new blocks have a sloping deck of up to 0.004". When we're finished decking the block, it is accurate within approximately 0.001" from end to end. Many machine shops fail to catch this, as their machinery does not allow for such precision.

We then plate hone the block with our new Sunnen SV10 diamond hone machine . This advanced machine hones the block with a finish unlike conventional machines.

The final step is to clean the block in our high-pressure block washer. We recommend re-washing the block before assembly to ensure it is free of contaminants.

Rotating Assembly

Pictured below is the rotating assembly that comes with the short block kit. Please note that the pistons will be flat top.

Crankshaft Specifications

• Crankshaft: Genuine Manley
• Crankshaft Stroke: 4.750"
• Crankshaft Material: 4340 Forged
• Journal Diameter: Standard BBC
• Rear Main Seal: 2pc RMS

Connecting Rod Specifications

• Rods: Genuine Manley
• Rod Type: Manley Genuine H-Beam
• Rod Length: 6.700"
• Rod Material: Forged 4340 Alloy
• Rod Bolt/Cap Screw: ARP 8740 Cap Screws

Piston & Ring Specifications

• Pistons: Wiseco Fully Forged, High Performance for street/strip use
• Piston Size: 4.600"
• Dome Volume: -3cc Flat Top Pistons
• Compression Height: 1.115"
• Piston Material: Forged 2618 Aircraft Alloy
• Piston Rings: Mahle High Performance, Moly, Standard Tension
• Ring Size and Fit: 1/16, 1/16, 3/16 File Fit
• Ring Material: Ductile Iron/Cast/Stainless/Moly

Bearing, Damper, and Flexplate Specifications

• Main Bearings: Clevite or King MB557HP High Performance
• Rod Bearings: Clevite or King CR807HP High Performance
• Balance: In-house on CWT balancer
• Damper: ATI brand 7.074"
• Flexplate: Heavy-duty 168 tooth or 153 tooth, manual transmission flywheels available

Compression Ratio Chart

The calculations below were done with pistons at 0.005" below the deck. We usually deck the BBC blocks down to allow the pistons to sit 0.003-0.005" below the deck. Zero deck is most optimal on SBC engines, but BBC pistons tend to have a bit more piston rock than SBC pistons. We used a 4.630" head gasket diameter and a 0.040" head gasket thickness in our calculations to determine our compression ratio values.

Our custom-made Wiseco pistons are highly regarded in the street/strip performance industry. Wiseco offers several grades of pistons, starting with the lower grade Pro-Tru Street version made with 4032 forged alloy. The next level up is the professional series, which is more expensive and made from 2618 aircraft alloy with fully machined crowns rather than the as-cast crowns found on the Pro-Tru series. Our Wiseco pistons are custom-made for us, incorporating both of these premium features: 2618 alloy and fully machined crowns. All premium grade forged pistons on the market have these two unique features and typically cost around $800-$1100 per set.

We prefer the 2618 alloy over the lower-cost 4032 alloy. The 4032 alloy may fragment due to detonation, which can be highly destructive to the engine. While 4032 alloy pistons are fine for stock or mild engine builds, they should never be used in carbureted engines built for high horsepower levels. The forged 2618 alloy piston is much more resistant to detonation and heat.

We have built approximately 8000 engines using Wiseco pistons over the past 10 years, primarily for street rod and strip use. We have experienced no issues, nor have there been any complaints. These pistons are excellent in every respect.

Important Note on Piston-to-Wall Clearance

Many customers ask what size they should bore their block to allow for proper piston-to-wall clearance. The required clearance is already built into the piston. For example, if these pistons show a given size such as 4.030", that is the exact size to bore the block. The actual size of the pistons, when measured at the skirt 1/2 inch above the tang, will be approximately 4.026". The needed clearance is built-in. If you are using these pistons in a marine application where the boat receives its water from the lake, add an additional 0.0015-0.002" to your final bore size. Some forced induction applications may also require a slight increase in bore size.

These pistons are suitable for use with mid-level nitrous or blower setups. Extreme level builds that are making horsepower numbers in the 1000 HP range will require a set of custom-made extreme duty pistons.

Our Wiseco Forged pistons are custom designed with an increased compression height, which offers many advantages. Here are a few facts about compression height and deck height:

Our custom-made pistons have a compression height that is 0.010" taller on BBC pistons and 0.015" taller on SBC pistons compared to most catalog pistons on the market. We find this to be a very valuable feature.

Since our pistons sit at a taller than normal compression height, we only have to remove approximately 0.005-0.010" off the deck surface of the block. Our goal is to set the piston at zero deck (flush with the deck surface). This maintains the deck's thickness, making it much stronger than a block that has been cut down 0.025". The engine will also run a bit cooler with a thicker deck, as the deck dissipates much of the built-up heat an engine generates. This also allows for future deck re-surfacing without compromising the integrity of the block. On our BBC engines, we actually leave the piston about 0.003-0.005" in the hole to allow for possible piston rock. Our SBC engines will have the pistons set right at zero with the deck.

You may have noticed that our Wiseco custom-made forged pistons are referred to as "Racing Pistons" on the package. This does not mean the pistons are for racing only. This is a generic term referring to their ability to be used in high-performance applications as well as for street rod use. These pistons are perfectly designed for use on the street, as well as for medium to upper-level drag racing.

Manley Pro-Series Crankshaft

The New Manley Pro-Series #190280 with 6 counterweights, 4340 Forged Crankshaft.

Some of the benefits of the new Manley Pro-Series crankshaft include:

• Considered a top-tier level crank compared to more common brands
• Forged 4340 construction with a multi-step heat-treatment process
• Nitrided for added strength
• Stress-relieved, shot-peened, and magnafluxed
• Micro-polished large .125" radius journals, gun-drilled mains, and lightened rod journals for weight reduction
• Counterweights are fully profiled and designed for internal balancing
• Includes a spec sheet that validates journal sizes, checks for taper on each journal, and verifies finish quality

As of May 8, 2024, we have now upgraded all of our 632 engines and 632 short block kits with the Manley Pro-Series crankshaft.

Thrust Clearance

We recommend that you check the thrust clearance on the crank before assembling the engine. This is advisable for any crankshaft, regardless of brand or cost. Also, be sure to check your main and rod journal sizes.

Rods

Our choice of rods is the Genuine Manley 6.700 H-beam rods with ARP 2000 cap screws. The Manley H-beam rods are highly rated in the racing industry and easily outrank most other common brands on the market.

All of our engines use the ARP 2000 rod bolts.  The rod bolts are most likely to fail under hard use, more so than the rod itself. When a rod bolt fails during high RPM, total engine destruction is usually the result. The ARP-2000 rod bolts are superior to the more common ARP 8740 bolts, in our very strong opinion. Those who run hard always use the ARP-2000 rod bolts in their rods. The ARP-2000 rod bolts also torque at a higher number, and this increased clamping force is also a factor in keeping the rod cap from "walking" as it's referred to. It is this minute repetitive amount of cap walk that over time stresses the rod bolt and often leads to a major engine failure.

Rod Sizing

Before the engine is assembled, we strongly suggest checking the rods on a Sunnen machine for sizing on both ends. We recommend this with any rod, regardless of cost or brand. It is not uncommon to find some rods requiring a slight bump through the hone for perfection in sizing and roundness. We offer a "Rod Proofing Upgrade" for this set of rods. It's an excellent choice for those wanting to build the engine on their own.

Total Seal High-Performance Rings

King or Clevite brand bearings, depending on availability, main and rod bearings included. We most often use the Clevite bearings, but due to shortages, we are sometimes forced to use the King HP bearings. Both are high-quality bearings.

BBC Chevy ATI Super Damper, SFI Rated, Internal Balance, 7.074" for BBC Chevy

Please read this complete ad to better understand why the use of a premium damper is a must on most high-performance engines.

The patented ATI Super Damper standard harmonic balancers are designed exclusively for high-performance engines. Inner and outer shells are available in aluminum or steel and contain a steel inertia weight. The inertia weights have six (2-ring design) or eight (3-ring design) computer-machined grooves to retain the proper durometer O-rings (dyno tested for each application). Whether you race or just drive on the street, ATI harmonic balancers are the perfect choice.

Features Include:

• Eliminates torsional crankshaft vibrations
• Exceeds SFI 18.1 specs
• Black zinc chromate finished
• OEM equipment on a variety of crate engines
• Tunable, re-buildable, and extremely efficient at all rpm
• Laser-engraved 360° timing marks

We have noticed others using low-grade knockoff brand dampers/balancers, and we have encountered them in the past. They are substandard in appearance and are often out of spec. The timing marks were also poorly marked on some of the balancers we have come across. You don't want a balancer coming off or one that is improperly weighted. Another problem with low-grade dampers is that the elastomer bonding can lose its adherence to the inner and outer structure.

Heavy-Duty Flexplate Included

The heavy-duty flexplate included with this assembly will resist cracking. One good telltale in identifying a low-quality flexplate is the lack of welding on each side where the plate mates to the ring gear. They usually have a pale grey color as they are not coated and will rust quickly. Our flexplates are welded on both sides, much thicker than an OE plate, and are either zinc dichromate or black powder coated. We would never use the thinner OE-style plate on an assembly like this.

We do offer this assembly with a manual flywheel. See our other listings. In most cases, we have both sizes, 153 and 168 tooth, available.

Important Flexplate Installation Note

WARNING: The flexplate and crank have a dowel pin hole. You must align the flexplate and crank dowel pin holes, but do not use a dowel pin. The flexplate was aligned to the crank when we balanced the assembly and must be installed the same way.

Our CWT 5500 Balancer

We do our own balancing with our state-of-the-art CWT 5500 Series balancers. The CWT 5500 is the ultimate for precision balancing. We now have three of these in our machine shop. We consider this machine to be highly advanced compared to the Hines balancer we once used. We balance every rotating assembly we sell within 2 grams or less at no extra charge. A balance sheet is included with your assembly.

If you plan to store your rotating assembly or short block kit for any length of time, it is very important to protect these parts by spraying a light coat of rust preventive substance on all bare metal parts. This is especially important for those storing these parts in a high moisture or humid environment. Very light surface rust is easily removable and will cause no harm, but heavy rust can damage these parts and be very costly to fix.

Our Thoughts on Competitor Offerings

Many short block kits on the market do not use the most suitable parts. We hope you value the fact that we have put together an above-average short block kit. The failure rate with the parts we use is near non-existent. It was through trial and error in years past that taught us where to draw the line with low-cost parts.

We are out-priced by many others selling short block kits that include parts with high failure rates. Many of these parts also pose a significant problem due to the fact they require additional machining and can end up costing you a great deal more money and time. If you're going to have a machine shop build your engine, we strongly advise you to get an opinion from them on the parts you're going to be bringing to them. Rest assured they will find no problem with the quality of our parts.

We have also seen sellers offering parts that are not compatible with what most people are building. We have seen several sellers offering no-name brand rods with an assembly. These types of rods also have no-name bolts in them. It is our strong advice to avoid this grade of rods. The low-grade dampers and flexplates are also another problem.

Another area of concern is balancing. We are not sure how much attention these sellers are giving in this area. We spend up to two hours balancing an assembly, using the very best up-to-date balancing equipment on the market. If the assembly is not balanced properly, it will hammer the bearings out of the engine, not to mention that there is nothing worse than an engine that lacks a smooth feel and sound when under load.

Available Upgrades

We offer this short block kit with selected upgrades. Listed below are some of the most requested ones. Many not only improve performance but also enhance the reliability and longevity of your engine, along with resale value.

SFI Certified Flexplate

The cost of this upgrade is $24.50. This is a very low-cost upgrade and may be required when racing your car at certain tracks. The flexplate that comes with this assembly is a heavy-duty plate, but the SFI certified plate is one step up in quality and safety. This SFI plate is made in North America. We noticed these have much less run-out and warpage than we see with many other plates on the market. Plates with too much run-out and warpage can cause a host of problems for your transmission and starter and affect balancing. The low cost to upgrade to this is well worth it, in our opinion.

SFI Rated Billet Steel Flywheel Option for Manual Transmission

Upgrade to an SFI billet steel flywheel with 168-tooth or 153-tooth for manual transmissions. We highly recommend the SFI billet steel flywheel for those running hard. These are fully CNC'd and far superior in many ways compared to the regular cast iron flywheel.

The cost for the SFI billet flywheel option can vary depending on availability. We carry two lines of the SFI plates, PRW and Ram. The Ram plates are a much higher-grade product. We have this upgrade/option featured in our other listings. There will be a Chevy 153 tooth and a Chevy 168 tooth size available. Be sure you know the size you need.

Crank Polishing

The cost for the crank polishing upgrade is $39.50. This extends bearing life, reduces oil temperature, and frees up a slight amount of average horsepower. This is a very low-cost upgrade, and in the world of mass production, most cranks do not come with a true polished finish. This is why most machine shops have a machine to do this. The difference is dramatic between a crank right out of the box and one that we have polished.

Bearing companies claim that cranks with better finishes on the journals will survive the break-in better and have much longer bearing life. We do a two-step process and bring the RA numbers down into the single-digit range. We have the most advanced crank polishing machine on the market.

Rod Sizing

The cost of this rod sizing upgrade is $89.50. Sizing the big end and wrist pin bushing on the Sunnen machine saves a trip to the machine shop. All rods, regardless of brand, should be checked for sizing on a Sunnen machine and corrected if needed. You will seldom see a complete set of rods with perfect sizing on both ends right out of the box.

Race Balancing

The cost of this race balancing upgrade is $125.00. This is for those who want the engine to operate virtually vibration-free at high RPM. This extends engine life and frees up a few more horsepower. This is a somewhat labor-intensive procedure and is not required, but the feel of an absolutely vibration-free engine at high RPM is desirable for many.

The standard balance job that is included with this assembly at no extra charge is certainly sufficient. With a race balance job, all pistons and rods are match weighed to within 0.2 grams or less, and the final balance is brought down to around 1 gram plus or minus. An ultra-smooth engine at high RPM has a noticeable feel and sound. If you do not opt for this upgrade, the assembly will still be fully balanced. We spend a good hour and a half doing the regular balance work, and it will certainly meet your needs.

Block Prep Package (632 Only)

The cost of this block prep package is $395.00. This upgrade includes notching the block on our Centroid CNC machine to allow additional clearance for the crank if necessary. We also de-burr the block, hone the lifter bores to spec, chamfer the top of the cylinders and lifter bores, and install the special cam bearings and freeze plugs. The block is then thoroughly cleaned in our block washing machine. We find this upgrade essential for those lacking the proper equipment or knowledge to perform this correctly.

BBC Short Block Kit Assembly Upgrade

The cost of this BBC Short Block Kit Assembly upgrade is $695.00. This upgrade includes everything in the Block Prep Package plus assembling the short block kit. If you choose this upgrade, DO NOT also include the block prep package in your cart.

The upgrades listed above are all available in our other listings. Many of these are often requested by those building an engine without a machine shop. We find most of these upgrades very valuable for those wanting to take longevity and durability to the next level. They are all bottom-end related, and that's an area worth investing a few more dollars into, especially if you're planning on running long and/or hard. These upgrades are also valuable for your build history on your engine and would certainly increase the resale value of your engine should you ever sell it.