Engine Build Tech Help

So I'm trying to rebuild a 318 to throw into my Valiant. I've posted a couple other threads about this build and this is the latest update with me feeling like I'm either in over my head, or just got too excited about parts and didn't spec the correct parts.

Basically I picked up a .020" over 318 block for 800 bucks, it came as essentially a disassembled long block with a ton of parts. Freshly machined, new cam bearings. I've verified that the machine work is a consistent .020" and am fairly confident with the bearing side of the equation in terms of mains and rods. The block came with .020" over KB167 pistons and Hastings rings, as well as mystery rings installed onto stock replacement .020" over pistons.

Right now I'm a bit stuck designing the engine, I figured that my '69 block I was running before had about 9:1 compression or thereabouts, so I figured a bit more was a bit better. I'm reusing the heads from the old motor, they measured out to 63cc. Per my thread about ring gap a few days ago, it came up that my dynamic compression ratio might be too high to run iron heads and pump gas, so now I'm second guessing myself.
Hastings Ring Gap?
I have a Hughes engines hydro roller cam to put into the motor, I failed to break in my cheap cam swap earlier this year, so I decided it was worth my money to not worry about breaking in a cam. PN: HUG SER1822ALN-10. Since the only numbers I have for this cam say it intake close is at 35* ABDC, I plugged that into the dcr calc. With the static compression ratio right around 9.0:1, I am getting a dcr of 8.4:1 at sea level (I will be able to drive the car to the ocean, so this is a realistic worst case).
According to the wisdom of the forum (and I don't mean that jokingly, most of the advice I'm getting is coming from guys who have been building motors longer than I've been alive) I want to see less than 8.0 dcr. I might be able to get there by moving cam timing (assuming piston to valve clearance is sufficient), or by changing my build path to the stock replacement pistons.
Any guidance on what the best path forward is? Goal is for a fun cruiser that I can occsasionally take to the autocross, so pump gas is important, and I'd rather have the car be driveable than super highly strung and hard to tune.