273 Commando Engine Build

What year Commando engine will you be getting? What transmission. Will you be running headers or original manifolds? Original heads flow better than 302 heads, unless the 302 heads are ported by someone who knows what they are doing. When you get the engine check head castings before you do anything. Then have your block checked to see what diameter the cylinders will clean up before buying pistons. You can also go wild and run large port milled 360 heads with 1.88 intake valves, but you have to check for interference carefully. Anything with more flow will only push you past 7,000 rpm if you do everything right. If running 66 up small port heads (273 and 318) Weiand makes a nice dual plane, Holley Street Dominator is a low rise, good all around, universal carb, single plane intake. Offenhouser also make a nice intake that will also fit 64-65 heads. Of course there is the original Edelbrock D-4b for 64-65 heads or the LD-4b for 66-up heads. You can also run later intakes on using angled washers on 64-65 heads. As for a Cam an Isky E-4 is as close as you can get to an original Commando off the shelf. Isky, Racer Brown, and other good cam companies will also custom grind a solid cam exactly for your combination. With good machine work, stock heads, E-4 cam, stock intake and carb should make 265 hp with flat top 2 barrel pistons.