Intake Manifold

[sinsheep]

Need to know why a 4881 two four barrel intake will not fit my 333 truck heads. Really want the look but heads are already done. Have the original truck intake but prefer the dual quads. Help.

 

[jim_ss409]

The 881 manifold almost fits and with a bit of work you can bolt one on but it's not the ideal setup. The ports on the high performance heads and manifolds are about 3/8" taller than the ports on the 348s or low perf. 409s so there is a bit of a mis-match there. The bolts that are at the top of the ports won't line up but the manifold will seal up fine without them. It would probably be best to get 4 3/8" set screws to plug the holes in the heads and I think you might have to grind a bit off the manifold to allow clearance for the valve covers. lots of guys have bolted on the high perf. manifolds and they seem to work just fine but another way you could go is to sell the 881 manifold, I think they usually go for about 2 hundred on E-bay, and get an Offenhauser dual quad manifold that's made for the smaller heads.

 

[bluescreamer]

I concur with Jim, with what he said. I did this same swap 43 YEARS AGO
on a 348 motor that I raced, with no ill affects.

Allen