Just wondering if anybody has an idea if I put on a full exhaust how many mpgs I could pick up?

 

Single or dual? cat back, muffler back or true dual? What diameter pipe?

 

All I can find online are the kits that are 1 in 2 out single but Id prefer true duals&headers with 2.5 or 3in

 

I replaced my muffler for a high-flow and gained 1mpg and noticed quite a bit more holding power on the hills. Plus the pre 98 models are seriously more resticted at the y pipe than the later models. For that reason you may get more efficiency improvement than I did in my 01 especially if you're doing the entire exhaust. I bought a new Y pipe and high flow cat to compliment the muffler, just waiting till I have time to install it. Definitely cut out your factory Y

 

Yep, the y is THE biggest restriction on these trucks. (probably closely followed by the mondo stock muffler.....)

Headers and a y- with 3" single exhaust, or, Headers and 2.5" true duals is as large as I would go. You aren't building a 10,000 rpm screamer, you want the smaller pipe diameter to aid in scavenging, and keep flow velocity up. Too large of pipe for the application and your bottom end starts disappearing.

 

gosh darn it...wth am I gonna do now?

 

Build a 9500 RPM one!