Re: 221 V8
Not to mention that the 221 has a 3.5 inch bore as opposed to the 4.0 inch bore that the 289, 302 and 351W share. The larger chamber would way overlap the 221 bore. Likewise, you cannot use 289/302 intake manifolds. They will bolt on, but the cross sectional area of the 286/302 intake manifold runners are about twice the cross sectional area of the 221 head ports. Bad flow problems would result. As far as I know, the only four barrel intake manifold ever built that will work on 221 heads was the Holley 221 - 260 - 289 Street Contender. You will have to solve a crank case ventilation problem because 221's used a draught tube attached to the back of the factory intake manifold. The Holley Street Contender has no provision for such. Everything else that fits the 289/302 will work on a 221, like headers, camshafts, rocker arms, timing components and hardware. a 221 would be great in a light weight, vintage style street rod.