Best Transmission???
 

Planning the build of a 72 C/10 with a built LS3 and was trying to decide which transmission to go with, the 4L60, 4L80, or maybe the 6L80/90. Any opinions are welcomed.. Thanks

Re: Best Transmission???
 

Th400

Re: Best Transmission???
 

For the OD on a LS engine... if money was not a concern then one of the new 6 speed autos

Re: Best Transmission???
 

350 Turbo..."Everything else is just a transmission" <---<< Just kidding...Dont know nuthin about the late model stuff ;)

Re: Best Transmission???
 

6L80/90
If money is no object.
Overdrive will save you some gas.

Re: Best Transmission???
 

With the 4l80 , and 6l80 , I believe you will need some transmission tunnel modification .If that does not bother you Id do the 6l80 , more gears-more fun , and driveability , I hope you have atleast a 3.73 rear gear . 4l60 should be relatively easy to drop in . I think with all or at least the two 80 series transmissions , you will need driveshaft modification

Re: Best Transmission???
 

Built 200R4 from a Turbo Buick

Re: Best Transmission???
 

If the man is building a modern fuel injected engine, why would you steer him to old school TH350, TH400, or 200R4 that won't really bolt up?

If you are making serious power, then I would say 4L80. If you can afford even more modern, a 6L80 would be nice. No experience with the 6L80, but the 4L80 is a pretty tough piece.

Re: Best Transmission???
 

Didn't need to modify my tunnel for the 4l80. I've heard the 6L80 won't handle as much power, but that was quite a while ago. I imagine by now there are upgrade kits that can handle just as much power but I'm sure they cost much more $$$$. If it's going to be built I'd avoid the 4l60.

Re: Best Transmission???
 

you can bolt anything to anything with an adapter plate, around $100 usually.

don't let a bolt pattern stop you from your dreams, move the bolts; not your vision.

Re: Best Transmission???
 

You can bolt any 350-400-2oo4r-700r4 to an ls3 there are converter and flexplate issues ,but they are small , .4 of an inch to be exact , no adapter plates needed . the ls3 engine is missing a threaded hole on the top passenger side , and its not necessary , 5 other bolts will hold it .

changing to an overdrive transmission is a great upgrade , as is the ls engine , hey it wont leak :metal: , along with the increased cruising speed you will be getting , Id defiantly upgrade the braking system , especialy if you have 4 drum manual brakes now , minimal front disc power , 4 disc even better , my 68 is running an ly6 ls motor with a turbo 350 behind it , probaly swaping in a 2004r soon for highway cruising

I see you mention "BUILT LS3 " Thats over 500 horse easy , please go for a quality 4 disc power system , hydroboost highly recommended