340 Intake manifold recommendations

Looking for some recommendations on a good performing intake manifold for my 340.
Here are my specs.

71 340 .040 over.
Keith Black pistons KB243
Comp Cam 2705 270/270 Duration .468/.468 lift 110 centerline
360 heads 2.02/1.60
Stock crank, stock rods.
Hooker headers
904 transmission with stock converter
8 1/4 with 3.55's

I have an M1 single plane intake that is a W5 intake and before I drill it out I want to know if its even a good intake for my setup. If not I would like to see if their are some better options.
I also have a fresh built 340 Thermoquad that I spent a pretty penny on and I would like to run on this 340. Not to many spread bore intake manifolds and I wonder if there is some power loss using a square to spreadbore adapter.

Thanks!