[Tom]

A open spacer increases top end horsepower like a single plane manifold does. A 4 hole swirl spacer increases lower end-middle like a dual plane manifold. I would not put another one on if I were you.

An interesting story- When I put my new vortec heads on my truck I took it out for a spin. The low end power wasent like it used to be so I tried taking the 1" open carb spacer I had on it off. When I took it out again the low end torque was way down even farther then before! When I got back home I put the spacer back on and regained some of that low end. Wierd huh?

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1978 chevy c10
383 stroker,10:1 compression,vortec heads, roller rockers,performer RPM intake, Demon 650 double pump carb, MSD ignition, headman headers, muncie four speed, 3.73 rear gears.