carb spacer height question

[george worley]

I have 4v cast iron manifold on my 390 with a half inch spacer. Would It be any advandage to go to a one inch spacer,The 390 is mildly modified with a 750 holley c6 and 3:50 rear gear.I'm wondering if I would gain enough to be worthwhile.

[VirginiaCityFord]

I think it would be benefical, although I can not tell you how much of a gain you would see. Another option would be to go with a low rise aluminum manifold. You would get larger, clearer air ways, and a lighter manifold.

[VirginiaCityFord]

I think it would be benefical, although I can not tell you how much of a gain you would see. Another option would be to go with a low rise aluminum manifold. You would get larger, clearer air ways, and a lighter manifold.

[fitzwell]

1 inch spacer will sharpen up the off idle a bit & can have some benefit at speed...not huge gains, but noticable. As stated above, a manifold change would be a wise choice, and shave about 80 lbs off the front of the motor.