I have a 360 that is .040 over with h116cp40 speed pro flat hypereutectic pistons. I wasn't the one that had it built. It has stock rods and crank. Any rough guesses as to what the compression ratio might be with a set of open chamber j heads?

I have those pistons, that are 27 in the hole. With a 65cc head came out to about 9.6 to 1 if one uses a 39 gasket.
I went down to 57cc and went with thinner gasket to get to 10.5

Roughly 9.3 to 9.4 assuming 70cc for the head, 9.6 block height, Std. Head Gasket and no decking.

What year 360? Sometime in the '80s they changed the stock deck from 9.600 to 9.577. Let me know and I'll do a real but rough calculation.

Shoot, I figured it out for the various setups

Newer 9.577 block, 0.040 gasket, 73cc head 9.59:1

Newer block, 0.028 gasket 0.032" squish distance 9.85:1

Old block, everything else the same 9.13:1

Old block, 0.028 head gasket 9.37:1

R.

The block is a 77. It's going in a w350 with an automatic and 4.10 gears. I want to build a torque motor. Im trying to figure out what cam to use. I was thinking about using the Hughes SEH1620AL-12. The heads have already had appropriate springs installed for big lift. They are 2.02 j heads. I will be running an edelbrock performer intake and headers. Any rough idea on how much power this could make?

Also thinking of going with a Hughes whiplash cam

Well my calcs are pretty close and I think it looks like you might be well off to use the Mr. Gasket 1121G or the Mopar Perf version of that gasket.

I think your first Hughes cam choice, the 216whatever, is a really solid choice. If you have to have the rumpty idle then the Whiplash is for you. Otherwise the first cam is IMHO head and shoulders above any rumpty idle cam if you intend to actually drive it. Especially in a pickup.

My guess-top dyno says, properly tuned you're knocking on the 300hp door with well over 400 lb-ft of torque.

R.

Thanks very much for your help dogdays

Thanks for your input b3 and jwilli

I have the SEH1620AL-12 in a 360 built almost the same. It worked good for me. My 360 is 0.030" over, about 9.5:1 compression using the KB-232 dished quench dome pistons, milled block and heads. After messing with those pistons, it would have been easier to just use the pistons you have.
The heads are J heads from Aerohead with the 2.02" intake valves and hardened exhaust seats. They are ported, but I don't know what they flow?
I was using the regular Edelbrock Performer that has the EGR (in case I needed to emission the truck.) I currently am not using the EGR, so the intake was tapped for pipe plugs and blocked off. The performer intake ports neck down to 318 head size, maybe 1/2" to 3/4" from the mating surface. Gasket matching the intake was pretty easy.
I used a Holley 670 cfm truck avenger carb on it.
I had the engine in my '84 Ramcharger with 3.23:1 gears and 30" tall tires. Converter was a stock hi-stall replacement. I used the 360 B&M flexplate and the engine was balanced with it, so I could use any normal balance converter. The converter was OK for daily driving, a bit tight, but that was fine with my gearing.
I rolled the RamCharger the engine was in, so now the engine is awaiting to be installed in a '69 Coronet 500 (318 car) with a 518 trans behind it. If I had the money, I though about having the engine dynoed just to see what it makes? My goal was about 350 HP and 400 ft/lbs of torque?