Will 73, 455, 4X heads bolt up to a 67 Bonneville 400 block? These heads would produce about 8:1 cr, I think. How about 75, 400, 6X heads? Thanks, Ed

Will 73, 455, 4X heads bolt up to a 67 Bonneville 400 block? These heads would produce about 8:1 cr, I think. How about 75, 400, 6X heads? Thanks, Ed

use the compression calculator at the classicpontiac site for these questions. You can look up any details you need there for the input values for the calculations.

Unable to find a compression calculator at classicpontiac.com. Majority of threads is car dealers all offering the lowest priced Pontiacs.

That web site is www.classicalpontiac.com - not classicpontiac