identifying heads for 273

bamacuda said
Lot of good info here. The engine is completely apart, the crank has been polished, it has .030 on the block and .030 domed pistons (previous rebuild, I did not know it had been rebuilt or i would have just run it) I want to build it to last and have a bit of spunk. I am trying to go on the advice of the machine shop that the 10.5:1 will be problematic. I am trying to get a good rebuild for this commando 273.

I was told by Tim Connelly, the cylinder head guru at CTC, that the early 273 heads were swirl port heads. I also know that some of the the 1966 273 heads with the casting #2658920 had 1.87 intakes and 1.50 exhaust valves. These heads would give you a little more spunk. There were also 920 heads in 1966 that had the 1.70 and 1.50 valves.