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Exhaust size - 305 SBC?

Discussion in '40- & 55-Series Tech' started by Eskimo, Jan 24, 2004.

  1. Eskimo

    Eskimo SILVER Star

    Likes Received:
    Sep 6, 2002
    Danville, PA
    I HAVE to swap from my dual pipes to a single. I'm on the hunt for the infamous rams's horn manifolds, and will get that slick crossover pipe that Texican uses on all of his installs.

    BUT - I have a 2" die for the JD2... and found some 2" OD exhaust tubing... so , in theory, I can bend up my own exhaust... saving me mucho $$$.

    But, is a single 2" exhaust good enough for a 305? I have dual 2's right now.

    Maybe the added backpressure will help my low-end torque, which I care most about?

    To help myself be comfortable with it, I'm justifying it this way: the exhaust is close to being completely straight (after the crossover pipe), and since the JD2 won't kink the pipe like a muffler bender will, it'll be a full 2" diameter tube all the way back, and my muffler is pretty good. (Dynomax Magnum/ultra-flo welded) 2 1/4" pipe from a muffler shop would certainly be kinked where it's bent, so I'm ahead of the game, right?

    Engine is a stock '85 305, with only a Performer intake and the exhaust being non-stock.
  2. nuclearlemon

    nuclearlemon not an addict Moderator

    Likes Received:
    Jan 30, 2003
    meh-ico, colorado
    2 should be ok. that's what i ran on my first cruiser (i had to put 305 in when i blew up 350 and only had $50 to buy a good running complete v8). a properly setup single exhaust can outperform dual exhaust and is much easier to deal with.
  3. hammerhead


    Likes Received:
    Jul 5, 2003
    Central, Utah
    You are correct - torque is your friend. We aren't drag racing. My exhaust was made of 2 1/2" with the "kinked" corners so in effect it is like a 2" pipe. It was setup for a 305 but now I run a 350 tow truck motor. Grunts like mad and sounds clean and throaty. Not sure what you mean about crossover but I made mine go under oil pan to left side of motor and back a couple feet before joining together in a high flow Y fitting. From there it goes through a flowmaster and out. Runs good and has great clearance.