@toolmanmike it´s the low comp 273 with flat top pistons 040 overbored
CR will be 8,8:1 (measured and calculated) with the given 318 heads ( #920 with opened up runners to 340heads size, bowl blended, valve bosses grinded down, exhaust runners and combustion chamber polished)
the guy which gave me the 340 cam - told me that duration should be somewhat about 210 Int and 220 Exh @.050" and lift should be .428" and .436" about as far as i know lift was about .429" and .444" maybe i should measure this
@moper i just had the same thought "what about running the Magum Heads on the 273" but it just leads to problems with valve size vs bore and also rocker oiling thru the pushrods will be the next issue...
