LS engine and THM400 trans?

[thedude327]

Just wondering if anyone has used this setup? What parts or adapters are required to make it work?

Thanks for any info
Paul

[Autokraft]

I have this setup in my racecar. All you need is the LS/Turbo flex plate made by TCI

[T_Raven]

I know the 6.0 with a 4L80E has a spacer between the flex plate and crank. I'm pretty sure using that spacer and flex plate will work. The bolt holes for the torque converter may be slightly off but some guys have oblonged those holes when putting 4L80Es in place of the 4L60Es in the newer GM trucks.

[COYBILT]

this spacer depends on the year of engine you have. My 99Lq4 didn't have a spacer the crank flange was just longer.

[JUSTANOVA]

advance adapters also makes a kit with a re-drilled ls flywheel for the th400 tourque converter and a spacer for the crank.

[thedude327]

Went looking for some weight info and found:

sbc iron approx. 575lbs.

ls engine alum. approx 416lbs.

thm400 trans. approx 135 lbs.

So it looks like using the ls/thm400 combo the weight comes in around 551lbs. and you keep your stock speedo drive and driveshaft length. Plus ls motors can be run to to 6500 rpm w/no drama. Aside from the tci flexplate and maybe a crank spacer, do the LS adapter engine mounts allow for a close to stock engine mounting location? It also looks like a rear sump oil pan may be needed, but other than that. Not too bad of a swap now that there is a distributor kit available for the LS engine and carb style manifolds are available.



Paul

[CreepinDeth]

sbc iron approx. 575lbs.

ls engine alum. approx 416lbs.

Looks about right. Mind you that's the all aluminum LS block.
Not the truck LS based Iron blocks.