Thinking of switching from M1 single plane to LD340 but LD340 would need to be milled to fit. Is it worth it?

Hi Guys,
So I'm doing a bunch of maintenance stuff on my car and have the drivetrain with front suspension out right now. My car came with an M1 intake on it and that's what I've been running for a few years (street driven) just because it was easiest affordable option at the time of my build. I've been sitting on a LD340 intake for several years and figured now is the time to swap it out, but my J heads were milled down, so the LD340 would have to be milled down too so the bolt holes line up.
My question is: Will I gain enough noticeable improvement by doing the swap to warrant having the intake modified, or should I just stick with the M1 intake for now?

340/416 stroker with mildly ported 2.02 intake valve J heads and no hardened seats, so I know they probably won't last forever.

Thoughts?

EDIT: after further findings, the LD340 does NOT need to be modified to fit. Read through the thread.

Thanks!
-Doug