Drivetrain advice needed

[Tinindian6702]

After thoughts of a BBC or an LS3 swap. I have decided to rebuild my 400 engine. I spoke to the builder and he recommended a stroker kit and aluminum heads. Should be about 525HP. So what have you used for transmissions in this example. Converter advice woulod be helpful also. I was thinking 3:73 gears. Any advice would be helpful.
thanks in advance. Mike

[TheJDMan]

Are you thinking manual or automatic?

[72blackbird]

Mike,
A 461 stroker with aluminum heads and the right cam will make 500+ hp and 500 lbs-ft. on pump gas all day long. 3.73 gears are a bit too deep for a Pontiac V-8 stroker or 455- unless you have the setup to hook up, any hard launch will just smoke the tires with all of the torque these engines make. I run 3.08's and the last 455 I ran (w/ ported no.64 heads) would still smoke the tires until it hooked up, and would run low 12's with a built TH-350 and 2500 stall converter. I'm currently building another 455 w/ 325 cfm e-heads from SD Performance and thinking I will need to upgrade my rear end to handle the power- most likely I will go with a Ford 9" and 3.25 or 3.50 gears with a built TH-400 for the time being.

Block choice is also critical, since not all Pontiac 400 blocks are created equal- the best overall 400 blocks to use are the 71-75 no.481988 blocks- these have 5 mounting holes per side to bolt into a variety of chassis, and can handle 600+ hp even with 2-bolt main caps and ARP main studs. Avoid using the 75-79 no.500557 400- it has undercut main saddles and a tendency to crack at the main cap dowels when 4.21", 4.25" stroker kits, or boosted power adders are used. Earlier 979xxxx 400 blocks are also strong blocks, but only have 2 mounting holes per side and need adapter straps to install them in certain chassis.

A built 700R-4 or TKO-600 should be able to handle the torque of a big bore, long stroke poncho.

Geno