Major upgrades! Any ideas on hp gains?

Hey guys long story short I had 318 heads on my 360, older edel. manifold, headers, and to my recent amazement 1 7/8" duals out the back.

Story with that, had a 318 for the build that turned out to be cracked. Too bad I had the heads rebuilt already. So on a High School budget the heads were ran on a 360 block a managed to dig up.
As for the exaust, it was a graduation gift that was inexpensive, effective, and much appreciated, but as I measured it today I was amazed at how small it is. Especially considering this used to run 14 flat w/ the exaust on. (not way fast but it is a seriously sufficated 360 here! lol)

Now for the upgrades: Rebuilt Jheads (nuttin' special)

2 1/2" exaust with a cross pipe and those typical turbo muffs

Unfortunately I have to put the ED 318 intake back on for the moment but it will be moving on as well.
But with the stock J heads vs. the stock 318 heads and the 2 1/2" with cross pipe vs. the 1 7/8" strait pipes w/ cherry bombs, what are your guys' bets for HP gains and Torque gains?

I think maybe bout 40 hp or so? let me know guys! lata'