675 v 920 home porting

vghoon said
I have a 318 ,904, 3.23 diff gears in a valiant coupe here in aus that's just a fun cruiser.
+030, ldb4 intake, voodoo 701 cam, edelbrock 500, currently has 675 heads decked .050 & cranking psi is 165, and is a fun package to drive, From memory the 675 heads on the car are at about the 63cc mark.
Do I start home porting the decked 675 heads or 920 heads as I still have to buy & put hardened seats in the 920 heads to start with before anything else?
The goal is to home port as the Thread has inspired me.

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That's really your choice ,if you're looking to just swap heads on in a day...but if you don't mind tearing it apart the ones you have , porting them re lap the valves back on the seats they came off of...n then put them together and stick'em back on motor...that's a great plan. 920 head are around 66-67cc
675 are around 68... so the 675 is smaller after the milling you had done.
Closed chamber or not wont matter much if the piston is a mile away from it, no quench.