[SD455DJ]

Masaki,

I see you are asking about engine upgrades to your 350 in the Street forums. If your Lemans is or isn’t an 350HO car, I, myself, would pull the 350, stick it under the workbench (if it’s numbers matching to the car) and go the stroker 400 route. Get a Butler 4.25” stroker forged balanced rotating assembly that will get you a 461 at .030 over, or 467 at .060 over. They make brutal torque off idle with any heads, stock 6x-8’s for 9.5 compression to ported aluminums. Get a good roller cam (many on this board cam help better than I, like Paul K…) and valvetrain, aluminum intake (your P4B), Cliff Q-jet, and good headers (Dougs, etc.), and you’ll be in the 450 hp/550 lbft torque with stock iron heads to low 500 hp/600 lbft torque with any out-of-the-box aluminum heads before you know. Porting will get you more! Make sure you get the block machined at a competent shop that knows Pontiacs.

You can get the same forged rotating assembly for the 350 for the same costs as the 400/455 blocks, but your giving up 100 hp/100 lbft torque at least. I'm guessing you aren't concerned about originality, so may as well go big. Anyway, something to stew on. If you want to continue with a 350 stroker, that is fine too. There is a really nice '70 Firebird that has a stroker 350 engine that's been in the forum's recently (SRMMM?), so maybe you could contact him for advice.

Don’t forget that making more power is going to expose the cars next weakest link…trans, rearend, suspension, brakes, etc. Build the Lemans so it can handle the power and be safe to drive.

Dennis