The rest of the combo matters (gear, tire, cam, planned use). That said a 512 EFI would probably like a single plane. Good breathing on top, good fuel distribution for EFI and you likely have more than enough torque down low with 512 CI.

I like and run a M1 single plane on my low deck EFI stroker. With a flat hood, and mild drop base air cleaner it fits (just). I am running port injection and a really short throttle body. I think the Sniper is TB injection and a bit taller.

If you have a raised hood (eg TA) the M1 should fit with TB injection. If running a flat hood too tall (I think).