1977 Chevy 1/2ton 4x4 SWB with small block 400 with stock 4bbl Qjet and stock intake (I will be staying with the Qjet but replacing the intake soon. ) Ok, so the existing collectors are crap, got holes sounds like junk. Currently i have true dual 2 1/2" pipes running half the length of the truck to cherry bombs. They sound ok, but with the leaks up front, it's killing me. I am sure i'm losing a ton of pressure up front when i accelerate. Stopped by a local shop today and talked with the owner, nice guy, and he suggested dual 2 1/4" Flowmaster headers to dual 40 series flowmaster mufflers out to stock side exits. Which is what I am thinking I want it to look like. He will do it all for $450. Question is: Am i going to be losing too much backpressure running true dual? should i go 2 into 1 with 3" pipe out?