Im looking for a new exhaust system for my 91 Pickup 3.0 and I was wondering what you suggest for size, or maybe you have a good site to look at. I currently just have a 50 series flowmaster on it. Im also thinkin about Downey headers and Y pipe. Thanks

 

for size, i wouldnt go over 2.5"

 

I went from stock cat, and 2.25" cat-back pipe with a straight through design muffler, to a high flow cat with a dynomax superturbo muffler and 2.5" pipe. I notice a difference in performance, even in the low end which I thought wouldn't be as good with 2.5" but it is

 

I have a Downey Cat back on order, we'll see how it works.

 

I'd go with a 2.5" catback and a dynomax ultra flow muffler. Let a local shop do the pipe and save some dough if you like.