high conpression head ??

[PC/SR]

I run a vintage Weiand head, 6.8 CR. On an engine dyno best HP at the flywheel was at 22 advance. The total advance for the A distributor is 40. Run the spark lever at about half way down on your total range. Every head and engine set up is different, but this should work for general usage. Mechanical or vacuum advance is going to take some work to modify depending on the type of distributor you have.