When should you go to a Dutra Dual?
My engine is basically stock in the 83 D-150 with 833 o/d.
head and block shaved 010 30 over pistons
solid lifters and 264s compcam
standard valves no port work or other niceties
I am thinking of running a big fat pipe from the Exhaust to the muffler,
( not changing this pipe is NOT an option anyway)Cats been scrounged, and pipe leaks,keeping the nice quiet muffler and 1 7/8 tailpipe.
would this be sufficient if so how big of a pipe? if not DD's?
suggestions?
robert

Seems like dd's would be a nice upgrade and would compliment your other mods. Most I think would agree that headers are a bit much(depending on the style, long or short) unless you have done a lot of engine work, and exhaust heat from the stock (or dd modified) exhaust definitely is a boost to driveability, at least when its cold. See agressive ted's page(linked in his signature) for pics and specs for an idea of what is possible with a one-barrel and stock manifold.
Seems like the most popular downpipe size for performance is 2+1/4.
If you go to dd's maybe dual 2" to a 2+1/4 y-pipe since you are keeping your current single muffler; and either should work good with your 1+7/8 tailpipe. Search User Zedpapa for some good discussions about exhaust diameter.

_________________
72 dart acquired 12/08 /6,holley2b, mopar perf intake, mopar perf header, cam, built motor,904 finally re-installed, 8.75....still needs sorting out.
99 dakota 318 5 speed reg cab picked up 9/09; Trans finally fixed! woohoo!

Dutra Duals are great for a stock slant, in my opinion. I have had Dutra Duals on my mostly stock '78 Volare for several years. I have the Dutra front manifold, and the modified rear manifold, and the two pipes going into one.
Even if you don't modifiy your slant six at all, you'll have peace of mind knowing that you're exhaust manifold won't crack.

"If the manifold wants to be two pieces, make it two pieces. Problem solved." Doug Dutra

I believe that's a direct quote, my apologies if it isn't.

_________________
"Ja, Ich fahre ein altes auto."
'78 Volare 225
'67 Charger 318