I'm going to put a 350 block into my '67 El Camino. Not having the 283 it originally came with, my question is: Is it a big deal to put a period-correct intake manifold (with oil filler tube) onto any old late-model 350 block? I already have the plain "Chevrolet"-script valve covers, and I know all 350s after '68 had the oil filler on the valve covers. I just want a reliable driver, but I would like it to look correct under the hood whether the numbers match or not. Thanks in advance.