273 hop up help..manifold carb etc!
Yes,smallblock headders are smallblock headders 273 to 360 headders will bolt up. The only ones you gotta watch out for are the later 318-360 heads with the air injection ports. That's an easy fix just tap & plug them with small alen head plugs or tack weld them shut grind down & good to go! Where it gets tricky is what vehicle the haeders are going in. That's where its different early A's (63-66) is real tight & good headders that fit will cost you! Now 67-76 there is lots of choices. id use the smallest primary tube headders for a 273 otherwise it will not help low end torque @ all! Ask how I know LOL!