I just finished rebuilding my engine and I was wondering what HP should I expect.

502MPI Gen 6
Cam 741
1.8 rollers on intake @ 2.19 Valves
1.7 roller on exhaust @ 1.88 Valves
Cyclone Headers with dry exhaust
reprogram ECM
Short runner intake
Ported heads with tri angle valve seating.
MSD kit
K&N Flame arrestor

Any suggestions.

High 500's to low 600

High 500's I was thinking somewhere around 525. Well that's good news. So I should expect high 70's on my 22 scarab.

I would think it would get into the low 80's, depending on the lower unit and prop.

2'' shorty Imco lower, 27 Quad 4 lab finish and 26 P5 lad finish by Throttle up.

I would say closer to 525 as you were thinking. A lot more factors than you listed. It will depend a lot on the what heads and comp ratio.

550?

Griff, as regarding the ratio is 9:1, as for the heads I worked on the standard GM head cause I ran out of money and secondly since we use the boat in salt water only, aluminuim heads was not an option. I think that 525 is more realastic but what is above that, it's always a plus.

Thanks to all that sent their suggestions

Have fun and play safe.

Id guess in the mid 5s too. with the 741 cam are you gonna spin it to 5800ish, isnt that cam good for up to 6000, i suppose your whole setup dictates that too.
a guy locally ran his aound 74 with stock 502 so i would guess right around 80 or more.
b70

Eyeburn, close to 80 was my final goal. Now I have to wait until I'll run it and see whats gonna be the end results. I will keep you posted.