wrenchmaster Posted September 23, 2013 Share Posted September 23, 2013 I am trying to put my 1970 402 big block back to as close to factory as possible. Problem 1 had the motor bored .030 over rebuilder put in pistons with a dome of .110 height (this was 25 years ago) i remember them the originals being a taller dome does anyone have a 1970 factory piston they can measure dome height on or where I can find exact duplicates? problem 2 I have a print out on the build book for 1970 monte it shows 2 different specs on factory cam shaft it shows the lift as .3983 for both intake and exhaust in another spot it show .430 for exhaust which is right and where can I get a cam as close to factory if the second spec is right? crane cams has a blue print .398 Thanks Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted September 23, 2013 Share Posted September 23, 2013 I would guess that the lower domes were installed so the engine would run on the lower quality fuel. If you actually find the taller domes you may run into drive ability issues. 10.5 to 1 with cast iron heads is not a fuel friendly compression ratio. Camshaft number = #3874872 Camshaft Intake duration @ .050" == 196° Camshaft Exhaust duration @ .050" = 196° Camshaft lift - Intake == 0.398" Camshaft lift - Exhaust = 0.398" @ 114° LSA Quote Link to comment Share on other sites More sharing options...
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