Going strictly by the numbers...... in that 118-120mph area, at around 3500lbs...... if you don’t waste any of it....... a tenth is a little over 1mph...... which is worth about 15hp.

So, that seems like a reasonable expectation to me.

Interestingly....... the motor your cam came out of was swapped to a roller.
That was a 6bbl though, and the heads got updated a little at the same time.
I think the gain was over 3 tenths(or more) with that combo.