302 casting swirl port heads

The 273 pushrods work fine with a flat tappet cam. If you want roller lifters, use the '86 pushrods and the valley plate that holds the roller lifters.

Since you mention keeping a 10.5:1 compression ratio, I'm assuming a Commando engine that has adjustable rocker arms. If you're using solid lifters, use the 273 rocker arms, if using hydraulic, use the arms from the '86.

FWIW: I had no "smog" holes under the exhaust ports on my 302 heads in the Demon. If present, do per 66dartman.