ICON 9976 with Magnum Heads?

If the deck height is nominal and this is an LA block, then these will sit about .011.012" down in the bore. That is a .050" compressed gasket (typical, reportedly can vary some) and a 4.18" bore hole. Head cc's ought to be in the 62-63 cc range typically.

With those nominal and typical numbers, static CR will work out to around 10.0. With that cam, dynamic CR will work out right at 7.7 with that cam at an ICL of 110. Will run fine on the street and be very torquey down in the low RPM's. You will have to pay some attention to the tuning and ignition timing and not be lazy on that count, but it won't be very hard to get it to run well and avoid detonation on pump premium.

You ought to get the rotating assembly re-balanced with these pistons; with stock rods, you're dropping the bobweight 40-50 grams lower than stock; that's well outside what folks consider to be the sloppy factory range.

What is the planned use for the car/engine? Trannie type? There are better cams IMHO, but, IMHO, whether it is worth changing depends on what you want to do, the transmission type, and how hard core you are about torque/HP.
I had the assembly balanced while at the machine shop. Also had ARP rod bolts installed and rods resized. The car is going to be a cruiser that will occasionally see the local 1/8th mile track. It has a 67 model a904 and that’s the main reason for the smallish camshaft because it has 19 splines and I can’t get a stall convertor for it. The rear in the car is an 8 3/4 with 4:30 gears on a 28 inch tall drag radial. I was planning to do the IMM aluminum heads but have had to change plans to get something less expensive that will still perform well. I figured the magnum heads would fit the bill. I’m hoping this setup will get me in the 350ish HP will close to 400lbs of torque. I might be way off here I don’t know