Will 318, 340 or 360 heads fit on a 273?

A stock 66 273 will have closed chamber heads. Pistons should be around .020 in the hole at TDC. The 66 heads flow better than the 68-70 675 heads. 1.88 valves in a 273 is a must check. I would advise keeping the stock valve sizes. Probably not 920's but about equal. 57cc is NHRA minimum and it takes a .040 cut to get there.