I have an M1 single plane on my low compression 360 with a comp XE 268 and low end Tq is no problem even with the 2.76 suregrip and stock 318 TQ converter. Throttle response is great. Bolt your intake on and don't worry about it, you have a lot more cubes than I do.

My only concern is the top of the bore being distorted, you will be getting a lot of blow by with out a fresh bore/hone. If you really want more compression and your bores are still good then just mill the deck of the block .060 or so and use a thin head gasket and keep the original pistons with ne rings.