kind of new to this so here goes. I currently am restoring a 68 camaro. Right now i am building a sbc with around hopefully 400 hp. what my question is how will a turbo 400 react to that and any tips on the swap from the pg.

Th400 will handle that power fine. A TH350 will handle it also & it takes less HP than A 400. A 6" tailshaft 350 is the same length a pg so it is a bolt in. The 400 is longer you have to shorten drive shaft & get a TH400 crossmember.The yoke & ujoints are different also.Both the TH350 OR TH400 should have a performance build up for that hp range.

I have a th400 behind a 355 and you need all of the things that 67 Plum said. I had to slightly elongate the hole in the th400 crossmember though to get the bolt through but that was really the only customization that i had to do. I also needed to get a longer shift cable as well than the stock one.

But so far I like it just fine, any more questions just ask graemlins/thumbsup.gif

Well thanks but i have just have a couple more questions if i decide to use a turbo 350 will i need to modify the crossmember or will that fit also. Another thing in the past i have heard you know turbo 350 dont stand up to the 400 as well I never really understood is it because the ratios between or what? I am running a 10 bolt 3:73 gear in my rearend how does my combination sound to you guys. Thanks

The TH350 will hold up just fine. The only thing in a 350 to look at besides a decent rebuild and shift kit (or valve body swap) is to add in a good sprag race for the intermediate, or 2nd gear. I have had them behind some pretty stout smallblocks with no failures. I still have to laugh when I see someone telling that a Powerglide will have you cruising at higher RPM's than a 3-speed. Last I knew, the Powerglide's 2nd gear was 1:1, just like 3rd in a 350/400. In an all-out RACE appication, the Powerglide is usually the way to go in a car at or under the 3000-3200 pound area, as it will be quicker. In a lower-powered street or street/strip car, you will enjoy the lower first gear ratio of a 3-speed. Lots of guys have gone to O/D trannies as well. Thus, you can have a stiffer rear gear, and still keep the cruising RPM's down with the additional 4th gear O/D.

I have a buddy who uses a TH350 in his bracket car. It has stood up the the abuse with no problem (much to my surprise). I have no doubt a properly built 350 will take whatever your car will give it and, just as said before, while using less power.

I am recycling this post from awhile back, as I am contemplating the same change. But here's my question the Powerglide currently in the car is column shifted. What is involved in getting the turbo 400 to shift off the column. I believe that a t400 could be ordered with a column shift, but would imagine that to be a rare bird. This car is a 68 if that matters. Is the 400 cossmember still available from GM? Thanks