You need to mill those heads to get the comp up to 9.5 to 9.7 and that will bring the cranking compression to the needed 180 range that the 3.750" stroke of 350, 389 and 400 motors need so to speak.
This means you need a 10 cc reduction in chamber volume, so milling the heads .060" on the deck and the Intake flange will do the trick.
Note that milling this much off the heads means that you will have use only a bead of gasket maker on the valley pan and you might also need to trim some meat off of the bottom of the Intake Manifold to get things bolted up and sealed , but the power gain will be worth your time , money and effort!
Be sure that once the milling is done you lay a head gasket on the head and roll/ polish over any sharp edges of the deck that now stick out passed the fire ring of the head gasket.
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Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs!
And he was not talking about 1/8 or 1/4 mile ETs!
1) 1940s 100% silver 4 cup tea server set.
Two dry rotted 14 x 10 Micky Thompson slicks.
1) un-mailed in gift coupon from a 1972 box of corn flakes.
Two pairs of brown leather flip flops, never seen more then 2 mph.
Education is what your left with once you forget things!
Last edited by steve25; 10-18-2019 at 06:21 AM.
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