Tunnel Ram 383

Well, the car has a running engine in it now, so I can take my time figuring this out.

I have read up on calculating the compression ratio, but I am not sure I am knowledgeable enough to get it right.

So, the closed chamber heads will give me a lower comp ratio, which will allow me to run pump gas, and the open chamber heads will give me a higher comp ratio and might cause issues with pump gas- I think I got that right.

My guess is I need to figure the compression ratio out for the 915s to select the correct cam to use?

The engine has never been run, so one more thing solved.

The engine in the car now- I have no idea what the cam is or what the pistons are- I was told the heads were rebuilt and they do look damn clean. It has a high rise single 4 barrel Weiand on it, which is what was there when I got it.
Would it be beneficial to put the tunnel ram on the running engine to see how it runs?
I am going on the assumption that the compression ration would be the same on the old and new engine if I use the old heads on the new engine, and that the cam in the old engine is an aftermarket cam- is there a way to tell?

Just trying to think 'outside the box' so to speak- if there is no value to this idea then that is ok too, a gasket set and an afternoon is not a big deal.

I am thinking that the .030 bore must affect the comp ratio, and I have no idea if the old motor was bored.

I have a Lunati 60303 cam that came with the new engine, I wonder if this would work well with the tunnel ram?

Product Description
Hydraulic. The most awesome 268 cam ever produced! Out-powers all others! This High Performance street cam likes 2400 RPM stall, 800 cfm carb, dual plane intake and headers. Makes un-equaled power to 6200 RPM with proper valve springs. Very strong cam with great street manners.

•Advertised Duration (Int/Exh): 268/276
•Duration @ .050 (Int/Exh): 226/234
•Gross Valve Lift (Int/Exh): .494/.513
•LSA/ICL: 110/106
•Valve Lash (Int/Exh): Hyd/Hyd
•RPM Range: 1800-6200