Hot pipe thickness
 

Im building a twin turbo set up on my 91 one ton and was wondering how thick the hot pipe on a twin set up has to be? I cant find any 1/4in 2 1/2id pipe so could I just use 2 1/2 exhaust pipe or will this be to thin?And if its going to be to thin why does it have to be thick pipe?

You only need thick pipe if you are hanging the primary off of it. I'm using 3" exhaust pipe on mine, and it seems to be ok. The bottom turbo has its own mount though.