68project

Well, I just bought a LS4 303HP with 243 heads out of a '07 Impala SS. I'm hoping to get to 500hp with not too much trouble. Any suggestions on what auto tranny to throw behind it?

Mappinsj

interesting choice of motor. What are you putting it into and what do you want out of the car

Doug G

What trans you have now ?

What is the planed use ?

68project

Mappinsj- 68 Camaro
Doug G - no tranny, it's a roller, extreme roller. Daily driver that will get up and get moving.

Doug G

700R4 if you plan on lots of driving and any long trips

th350 or th400 otherwise

Or there are all the ones that come stock behind LS motors too

TH350 here but more short trips and drag strip.

68project

What are your thoughts on a 4L80?

Crf450r420

iTrader: (1)

LS4 is for front wheel drive and has different bell housing pattern. Also doesn't have the starter boss as it mounts in the trans on the Monty Carlo SS. You can change it over as we have done it two times. You need someone who can weld aluminum in their sleep and a clever machinist.

roth2000

If you want to make it easier on yourself buy a complete dropout LS with trans and you'll have the car up and running in no time. It's a little harder to find but I'd look for a 5.3 or 6.0 with the 4l80 to back it up. From there I'd add a turbo and you'll have a great combo with all the power you could handle.

68project

Thanks Roth2000. Found an LS4 w/243 heads that i couldn't pass up. gonna pull most of the innards and put in a 5.3 cast engine (gain a little weight i know), but for the price i just couldn't pass it up.