will this run on pump gas ?

No it's not going to run on pump.

Not enough cam duration to bleed off the static number. That's going to need a cam in the 240 at .050 to get it low enough unless you want a total timing number in the mid 20's.

Unless someone has cut rhs heads to 62 cc's, they have been showing up with chambers in the 68cc range most of the time, IIRC. Brian may be able to answer that better.

I agree with Dave, open the chamber up to get your static down and put a bigger cam in it.

Brian built a couple of 360's with RHS heads and XE275HL cam that run on pump gas. Don't recall the particulars but I'm sure they were KB107's.

Here' it is.
Stock 360 block .040 over
stock rods with arp bolts and resized
KB 107's
balanced
IMM RHS heads, no porting
comp is 10:1
comp 275HL cam on 112 lca advanced 2°
stock pan
PRW 1.6 rockers
rpm airgap
Holley 750DP
1" open spacer
TTI 1 5/8 step headers

425ish HP 440TQ