I am probably going with a LSX/th400 swap. I have spent some time reading the stickys and cannot find what I need to bolt the LS to the th400. Also, most swap articles I have read state you cannot use the factory crossmember, why not? I have a TH400 crossmember and really do not want to spend money again on another. Do the conversion mounts put the rear mounting flange of the engine in the same place as a SBC would be?

ls1 4L60E is different length than the normal non-ls1 4L60E is all.

So with a TH400 and the applicable crossmember I'm ok. Awesome, thanks.

yup along with the trans-dapt engine mounts from what i've been told. I'll find out this weekend for sure, since I need to drop it in.

The difference is the distance from the crank to the front pump. You'll need a spacer to go between the crank and flexplate.

Thanks guys, how did the engine mounts work out?

They didn't.....I don't know if it's the tubular kmember, the solid motor mounts or what, but nothing lines up and the engine is 1" too far forward and the mounts are 3/4" too wide so only 1 bolt will go in and the other one is 3/4" too wide so there's no way it'll mount up. Going to have to do some cutting and welding to the solid mounts, if I spend more than 2 or 3 hours on it, I'll just put a front plate in the car and sell off the conversion mount plates instead.

That sucks, sorry to hear that. Guess the spohns are the way to go.

with my th400 setup I used these:

flexplate #12551367
spacer #12563532
with spacer bolts #12563533

i used a standard wide bolt pattern torque converter too. put a washer in between the torque converter bolts with a healthy amount of lock tite and the input shaft was plenty into the pump

Thank You very much!