Dual Exhaust with stock exhaust manifolds:

[Stewart G Griffin]

That being stated, i'm probably just going to go the exhaust shop and have them connect the duals up to the 4.3's manifolds because it seems like it's the easiest/cheapest way.  This is not a race car and i don't plan on reving over 3000 very much.   i don't care if i lose a little torque, if in fact this is what happens if you run duals off of the stock manifolds.......

Then I guess it'd probably be a solid idea to wait until I had enough for performance headers and some new pipes.

i don't know much about exhaust.  i hear X or H pipes are a good thing.    From what i hear, if you get high quality headers you won't have problems that headers can bring.

But another thing to consider is the later vortec truck and corvette engines (just before they switched to LS engine) have some really good flowing stock manifolds.  So you might want to look at those as well.   i think corvette close to and up to 96 and i think the trucks switched over to LS around 2003? (not sure here)

[Irish_Alley]

Single 2"       pipe is good for 144hp dual 2"      is good for 289
Single 2.25" pipe is good for 185hp dual 2.25" is good for 370
Single 2.5"   pipe is good for 232hp dual 2.5"   is good for 460
Yes you can go too big and yes you can go too little.

[Kimper]

I am running true duals (2.5 I think) with stock manifolds on my 76 k10  BF GoodWrench 350 with edlebrock intake and carb. It seems to perform ok even with the 3.08 gears in it but I have nothing to compare it to.  I would like to put some headers on it just to see what it does performance wise.

[76LongBox]

I'm running basically the same setup as Kimper on my 76 GMC - GoodWrench 350 and TH350 trans (2 years old). Went with Dorman stock-style manifolds and true duals.  I do not know the rear end gear ratio, but the truck runs well and has adequate power/torque.  I too have nothing to compare it with other than the tired old engine/tranny that came out of it - but it always had true duals.  I have wondered if I should have gone with headers when I did the swap a couple of years ago, but I probably won't ever change it out.

[1979mmx350]

Kind of an off topic question but how much should I be paying for a new cat in CA? I've found a few ranging from $125 to $165.