Mark, I've studied my own project enough to be able to repeat this with some confidence: if you'll experiment placing the 'o' rings (and you have an assortment of thicknesses) on the tubes until you can just fit a 1/16" drill bit between the head and the gasket when it's floating on the pushrod tubes that spacing will give the optimum crush factor.
I'd bet, though, that you need new 'o' rings on the tappet blocks because the oil pressure in the pushrod tube is so minimal. Think about it, that feed comes from the rocker boxes and they're a drip feed from a 'Y' in the return line; the tappets are getting 80 psi. That means pulling the cylinders to replace the gasket on the tappet blocks...a good job for our friend Randy at B&A.
A positive attitude may not solve all your problems, but it will annoy enough people to make it worth the effort. Herm Albright (1876 - 1944)
