I don't know what gear ratio a 75 Hang 10 Dart comes with, but if it's a 2.45 gear all your listed choices will suck. I had a 72 Swinger I swapped a later A body 8 1/4 in, I neglected to notice the gear ratio till I took it for a test drive, 2.45. Even with a mild 360 swapped in (stock 79 360 with 340 cam, 600 cfm AFB, stock 4bbl intake) it was a slug off the line, but at about 70mph look out.

Before you decide anything, what is your rear gear ratio?

Robert, Much like the OP I have learned a lot with this thread. But I am now confused. On a theoretical build

360 engine - 0.030 over block, kb-190 pistons, .480/.480 cam, J heads with 2.02 and 1.6, torker intake and a 750 holley. complete MSD ignition, coil, wires, 6A unit. With the KB-190 at 10:1, how close will the Jheads put the compression at that actual number? Let's say standard 904 tranny and 3.23s in the rear, standard stall. Will the car be quick?

Since the block deck height varies & likely is greater than the 9.6" blueprint spec for a SB you could measure it as close as you can (use a round dowel in the bearing saddle & measure up to the deck + the math) or have your shop do it then with the rod length/piston CH/1/2 of stroke/valve reliefs/head gasket thickness/head CC's etc plug all that in to Wallace racings' calculator to get fairly close to your actual SCR in lieu of actual mocking up the short block. Just me I dont think 360 cubes and 3.23's will get you what you want. The few people I have talked to who have stroked a 360 say they would never go back to a regular 360. EDIT (1) decide on stroking or not (2) pick a cam & converter that you are comfortable with its characteristics (3) decide what octane you will run (or are willing to run) (4) figure what SCR is needed for that octane/cam to not ping or even be close to it & you want a cushion so you can run a fast ign curve (important) & gas ain't gonna get any better (& it is crap now) & E10 is spreading like a plague & being mandatory only type that you can get). I've always got a chuckle out of Nebraska being one of the top corn producing states in the nation & even with the intro of E10 here in the 80's (iirc) we always have had non ethanol gas available at the pump however it is as much as 20 cents higher than E10