So, after some casual observations it appears the HFV6 and LS bellhousing patterns are similar. Unfortunately I lack the means to measure and compare. Has anyone checked to see if they are even close? I was just thinking a LS3 and 6T75 might be kinda cool.

LS3 pattern: http://www.carcraft.com/tec...engine/photo_04.html

They are nowhere near the same. And the 6t70/6t75 are weird electronically speaking. I think it would take a lot of hacking to get it working with an engine it didn't come mated to.

Using the L99 programming for an LS3 might be doable though, with some hacking; as the L99 does come with the 6L80? in the Camaro. But I don't know how similar those transmissions are in that respect.

Thanks Dobey. I knew I should have just addressed this to you.

There was a shop looking hard at mating the 6T75 with the LS4 over on LS1tech... came to a screeching halt on the electrical/transmission control side. Give it a couple of years and someone will get it figured out.

quote Originally posted by fieroguru: There was a shop looking hard at mating the 6T75 with the LS4 over on LS1tech... came to a screeching halt on the electrical/transmission control side. Give it a couple of years and someone will get it figured out.

Yeah, the LS4, 4.5/4.9, and Northstar are really the only V8 options for bolting directly to a 6t70/6t75, as some vehicles do have that transmission with the Metric bell housing pattern. But the electronics side of things still makes it a very difficult swap. And the weird start mounts for the LS4 and Northstar still provide a hefty challenge there. I'm not sure there's room in either location on that trans to keep the starter in the factory locations for those engines.

I never new the Northstars got the 60* V6 pattern. I remember they initially had a special pattern shared with the Arora V8. I guess after a few years of cooking starters under the intake and all the $$$ lost in warranty work Caddy got smart.

quote Originally posted by Xyster: I never new the Northstars got the 60* V6 pattern. I remember they initially had a special pattern shared with the Arora V8. I guess after a few years of cooking starters under the intake and all the $$$ lost in warranty work Caddy got smart.

The Northstar pattern is slightly different, because the starter mounts between the cylinder banks. But it is possible to modify a Metric pattern trans to bolt directly to them. The N* And Aurora V8 are the same engine.

See some more info on N* pattern and trans modifications, starting here: https://www.fiero.nl/forum/F...L/000116-7.html#p261