My 1966 Valiant Effort

Yeah, I ended up calling Comp and giving them the spring pressure and stem height as the heads were already set up.
They recommended the XE268.

I had the heads set up for a Lunati but the Comp was about $65 cheaper and close in numbers. The Lunati had more duration and less lift.

The car moves about 10x quicker than that worn out 273, lol.
I need to play with the timing and play with jetting but right now, it starts right up and pulls pretty friggin good.