would my th700r4 bolt up to an LS1 engine? a friend from work is parting out a 99 trans am and he said hed sell me the whole engine for $500-600 and thats a deal and a half considering it only has like 10k miles on it and i dont want to pass it up. if i hav too ill buy his trans too but id rather stick with mine if i could. and are their rears good? might buy that too, thanks, please get back to me ASAP because i dont want someone else to get to this before me. thanks

Russ

 

No it won't bolt up; the crank is a different distance from the trans. Secondly, you'd have to fabricate a TV cable bracket & operate it from the TB, since zero LS1 TBs have TV cable provisions.

You shouldn't be too far out just getting the right 4L60-E and selling your 700. Get his tranny. And get ALL wiring from the donor car.

Matthew

 

would i need his driveshaft and rear too? and if i dont need them, are they much better than the stock ones in the thirdgens? if they are i will probably get those too because if hes selling the engine for 600 to me then im sure the rest will go cheap

 

Same length driveshaft.

A 2.73 automatic LS1 F will have a steel shaft.
A 3.23 auto or 3.42 M6 F will have an alum. shaft - get it. They're worth $150 or so - if alum., get it.

The rear will have good rear discs (better than 82-88 crap) so get it too. The width is wider. Search it up on here, a few guys have done the 4th gen diff. swap. It's still a 7.625 ring gear though.

matthew

 

ok thanks for the info, ill see him tuesday when i pick up my check and ill see what it has driveshaft and rearend wise, and ill ask for some more prices, and see if i can go check out the car to make sure everything is usable. thanks again

Russ

 

That is a great deal. I would take the whole drivetrain.

 

You are positive a th700r4 won't bolt up? I thought a 4l60 was the exact same transmission?

Isn't that what the Ls1 auto cars use?

 

He is positive. I do not know everything about transmissions, but I do know that our 700-R4's are hydromatic (operated and controlled by fluid, which relies on a throttle valve cable to keep the clutches from burning up, etc), the LS1 engines do not have this throttle valve cable bracket on the throttle body because the 4L60-E's (which come with the LS1's) are computer controlled (thus not needing a throttle valve cable). Also, the engines are designed differently, so they will not bolt up properly. I would just say go for the 4L60-E, or try and scrounge up a T56, which would be better, because trying to get the old 700-R4 to bolt up to the newer LS1 will be more trouble than its worth, and you will probably experience problems with it if you do find a way. Go 4L60-E, thats what I'd do.

~Mike

 

True, I just have a good th700r4 right now, with less than 2,000 miles on it. I love it, and would hate to scrap it so soon.

Wonder how hard it would be to put in a T-56...

 

The T-56 is the 6 Speed Manual trans used with the LS1 engines. You would need to modify your car with a clutch pedal, cut a bigger hole in the tranny hole, and a few other things, it all depends on if you know somebody who knows what he is doing. But the 700-R4 is not worth the trouble of trying to make it fit, the LS1 will probably shorten its lifespan anyway since it is such a powerful engine.