273 heads on a (1977) 318 block

Hi! I just bought a 318 block of 1977. I want to put on my 273 heads (1964) on it. I know we will have to adjust the bolts because of the different angle.
I just wondered if i can use the regular (flat) pistons of the 318 or can i expect to get problems with the valve clearance?

Wishing you a very good new year!

Arend
It doesn't matter if the heads are closed chamber or open chamber the valves are in the same location and height/distance from the deck. There'll be no problems with the valves interfering with the Pistons the only interference you could have is if you use some crazy pop-up Dome piston that wasn't shaped right for that chamber. The factory high compression Pistons are shaped specifically for that chamber and would not be a problem either.