Which turbo 400 to rebuild? Both are short shaft units. The 1969 unit is for a 400 4bbl gto or firebird. The 1970 unit is just a 455 non HO.
Are you putting them back in a code correct car? Rebuilding to resell them? Rebuilding to put them in another non-Pontiac car?
I have a 69 PS code TH400 in my 71 GS455 - I like it a lot. The PS was for a 350 HO Lemans or Firebird, so I'd assume the PX is pretty similar.
Doing the 455/350 swap, numbers matching do not matter. Both trannies happen to come with the 455 cores. So I can use either. Both trannies are are short tail shaft models, which ever one I use, will be rebuilt to handle a lot more power than a stock application.
In that case, I'd put them up for sale to see if there is any interest from the code correct crowd. I know it took me a couple years of looking to find a '68 PX for one of my Firebirds. If you don't get any bites, then I would do whichever one. I'm not knowledgeable enough to weigh in on whether either will perform better in the swap scenario.
Thanks woven web. If I find out both trans are really just the same cores, I will likely market one of them off. Thanks
