Would putting the hp525 cam in a 500hp give a decent gain?

If You Bring The Comp Up And Do Some Head Work.

That should be interesting

Sounds like a good upgrade to me.
From what I have read here on this forum, the 525EFI cam is a Crane 741 ground on a 114 lsa.

with the 114 lsa, is this cam better suited for efi than carb? will the 114 lsa give a flatter torque curve, but lose signal to carb when engine is at an idle?

My guess is that with the 114 lsa the vacuum would be higher at low rpm.
The 454/502Mag cam is the same for carb or EFI and I think 115°lsa.

I went with the crane 731.

I was just wondering why mercury racing would chose a 114 lsa instead of 112? is it because of overlap or water reversion? I've tried the 731 in a hp500, what it seemed to gain in midrange it lost some at top end.

I think its more the total package. The 731 is a 112lsa and the stock hp500 is 110lsa. The 525 cam is 114lsa.

Im hoping for some top end gains from the stock hp500 carb to the 731.

Great cam great combo ,go for it!