I've read all the stickies, all the FAQs, browsed Summit racing...But I still have a question. I am thinking of swapping in a TH400 for the big race weekends and keep the 4l60 for the daily drive. . The built 4l60 holds up great for the daily driving and handles an occasional shot of nitrous and lead foot but it's just not dependable on the stip. Now I've replaced the 4l60 so many times I can do it with my eyes closed and since it's so easy, I though hey for the big weekends, just drop in a TH400! Cross-member? Check. Tranny? Check. But I already have a stalled TC for the 4l60...I know a TH400 TC will bolt up to the LS1 flywheel with that spacer from Summit. But will my 4l60 TC fit in the TH400? If not...Are there any CHEAP spacers? If so...THANKS!! I really don't feel like spending $xxx on a new TC for the TH400 but if it has to be done it has to be done. Thanks again

OH! One more thing...Driveshafts. I heard that an M6 driveshaft will fit into an F-body with a TH400 swap no shortening or lengthening required. Is this true? And if so, which size tailshaft would I need for this to be done?

 

you need to get another converter.

 

you will need another converter, but you can get a flexplate that is drilled for both patterns.

 

your converter from the 4l60 will not work in your 400.You would need another converter.We offer a converter with the long pilot and correct bolt circle so you dont have to run the spacer.Simply bolt it right in.

Greg

 

Just a heads up, I had to get a new driveshaft made to work with the TH400 when I swapped from a 6 speed.

It was about an inch too long.

 

The driveshaft will be to long and it will take a new input shaft into the th400. I think you're getting the th350 and th400 stuff mixed.

 

Just did that whole swap went 4l60e to t400.
things you have to do are in the stickie under FAQ.
You will need a tci flexplate the sfi one that has the sbc patter with it or have a vender built you a t400 stall that bolts up to a ls1 flexplate if you are putting down any power buy the flexplate or yours will warp like mine and break
1 YOU WILL HAVE TO HAVE A DRIVESHAFT MADE COST ME $350
2.IF YOU DO RMVB THEN YOU WILL NEED A B&M RATCHET SHIFTER
3.STALL I WENT WITH A NEAL CHANCE
4.TRANNY T400 CROSSBRACE THAT OTHER CRAP OF USING A 6SPEED ONE DOES NOT WORK OR PUTTING SPACERS F THAT I CALLED YANK AND BOUGHT ONE OF THERE TRANNY CROSS BRACES.
5. CALL FRANK AT PERFORMABUILT ON THE T400 IT ROCKS.