Z head and O head on 1973 340

rumblefish360 said
Building this engine up like a speed shop got it and then “Enhanced” the package is a wide and varied list of parts to what company did what. Shy of piston replacement, getting the compression up on a low compression engine would require new pistons. Milling the head and then intake to fit is a good cheap route seldom done by way of compare to new pistons. Then the head itself has to be addressed. How far do you want to take it?

I was out in the parts shed today and looking over the stuff I'm taking to the swap meet to sell. I ran across some
3671587 casting heads that I thought were late 70's 360 heads. Those castings came on 1973 340's and 73-76 360's. Are they no different than any other 360 head with 1.88 intake valves?

I'm thinking I should probably keep them since they could be sent out and prepped and be ready for when I want to get a hotter cam and higher compression pistons.

Any insight on mods? Plunge cut the bowl and blend it? 5 angle valve job? Port match? I heard about a mod where the intake pushrod hole can be filled with a rod and relocated so the pushrod pinch can be addressed. I'd like to hear about that or at least get a link so I can read about it. I am guessing you would need some offset rockers from a place like RAS too.

I think I would want to use no lower than a 3.73 gear. 231/237 duration at .050" and .525 lift from Competition Camshafts. The car has subframe connectors and torque boxes. That cam calls for 9:1 compression. Would I need to get new pistons or would milling the head surface be required? I may not be understanding everything that I need to regarding the pistons height in the hole? I still need to confirm what pistons are in it.

Can I use a bore scope and determine if they are the factory piston based on the valve cuts? I am reading that the 340 was 8.5:1 so can I even make that up with head work and gasket and get 9:1?

Sorry about all the questions. I probably need to slow down and read more.