i have 2 standard bore 454's i like to get 500 hp to the prop with these motors NATURALLY aspirated. possible on pump gas? or do i need to search for a 502 or 540?
i have 502 ret port heads . how much you think i could have a 500 hp to the prop motor done for?

stroke them to 496. steel cranks. forged pistons. better rods. then you need induction-cam-exhaust that will be compatible with the 502 heads. that is assuming the heads work with the 454 blocks. time you are done, you will probably will wish you went and got 502's.

A pair of AFR 265 Oval Port heads, Marine Kinetics Cam, roller lifers, new push rods, new rockers, timing chain, exhaust- possibly swap out the intake and carb. All of this will get you around 540 hp maybe more and will cost you about $5-6000 in parts per engine. Machine work, assembly add at least another $1200. If you go 502's you're going to have to spend the same amount but now add the cost of the short blocks. If you stroke them you'll need all the above parts minus the heads but the heads and the rotating assembly will be a wash as far as cost goes. I'd rather have the better heads.

Are the 454's you're starting with Mag engines with forged internals? If not then stroke it, 330's don't like to be modified!

330's don't mind being modified, as long as they are modded with new cranks, pistons and rods!!!

2 bolt main 454's 502 heads i do have b&m 174 blowers

If you're going to supercharge them, I would suggest 4 bolt blocks. If your hell bent on using what you have at least stud the bottom end.

I recommend new heads, the Chevy Mark IV, V heads are the weak link and they leak around the 3,4 cylinders on both sides.

Bob Madera for a cam.

Wannabe