Thread: 429 build questions.

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Originally posted by BigNasty
My bro-in-law has a 429 in a 67 or 68 something TBird.
He is wanting to yank it and scrap most of the internals, keeping the crank block and heads to drop in a hot rod truck he is working on.

He wants to get at least 600+ horses without resorting to anything too exotic, such as a super charger or nitrous.

My question is: What should we plan on for pistons, the cam, valve sizing etc to reach his goal of a big horse carbed 429?

The 1968 429 Thunderjet from a T-bird is a great engine. The block and heads are strong, capable pieces in a performance application, and those parts can handle the 600 HP you are shooting for.

The heads should be casting number C8VE-A. This number can be found on the outside of the head, along the valve cover and between the 3rd and 4th exhaust ports. The Block should also be a C8VE-A casting, and its number is located behind the starter moter and reads vertically. Please confirm these numbers before moving forward, as different casting numbers may mean a different approach to your intended build.

For 600+HP, you must ditch the stock cast pistons and I strongly recommend replacing the rods. With proper rod prep and a few oiling mods, an occasional 6000 rpm is not a major issue, but for the amount spent on rod prep and good rod bolts, etc, you can buy some Eagle SIR I-Beam rods and they have a higher HP rating. A little overkill in the connecting rod department goes a long way, as the stock rods are prone to breaking in the mid-beam area.

One thing that will make your 600HP goal easier to achieve would be a 460 crankshaft. The only difference between a 429 & 460 is the crank stroke and the pistons (pin location). Every other internal component is identical and interchangable. IF you could stroke your motor another 31 cubic inches for an extra $50-$100, wouldn't you do it? Sure you would! So find a good condition 460 crank and make that engine a 460.

The C8VE cylinder heads have been dyno proven to 700 HP in a normally aspirated engine. Proper porting and oversize valves are necessary and this rings true for your 600HP build. Stock valve sizes are 2.08" Intake and 1.65" Exhaust. Re cut the valves seats for a 2.19 Intake and a 1.76 exhast. Enlarge and blend the valve bowls accordingly. Intake port is okay as cast, but the exhaust port will require significant grinding to free up exhaust flow. I strongly recommend you investigate proper porting of the exhaust port as removal of the wrong material can hurt flow.

For 600Hp from a 460, you should be looking at solid lifter camshafts

Suggested Ballpark Build:

• 460 Crankshaft, Eagle I-Beam Rods & forged pistons 10:1 to 11:1 compression ratio
  
• Solid lifter cam kit about .600 lift and 275* intake/280* exhaust duration @ .050" Roller rockers.
  
• C8VE heads big valves and ported properly
  
• Double roller timing chain
  
• Eldelbrock Performer RPM intake manifold.
  
• Holley 850 cfm carburetor
  
• Headers
  
• Quality aftermarket distributor

The above combo will get you in the ballpark, but I think it will take very good porting and perfect tune to pull off 600 HP. A reasonable alternative/upgrade would be the TFS SCJ aluminum street/strip heads or better yet the John Kaase SCJ aluminum heads. Either pair of heads purchased completely assembled will bolt on and then get a slightly bigger cam and Holley 950 HP carb on an Edelbrock Victor single plane intake. You will have your 600Hp for sure.

Another option is to keep the C8VE heads and instead of making a 460, you can buy a 502/514 stroker kit for about $1400. This kit includes crank, rods, pistons, bearings and rings. Simply bring to your machine shop for balance, block overbore, etc. Be sure to get a name-brand kit such as SCAT of Eagle. Buy from source and not ebay no-name kits.

Paul