Not saying that .I'm just confused and I want to do it right 1st time .I want the best performance for what I have. Don't wanna hurt motor .

Maybe it's because of the Bravo XR.

He'll be past the limits of it already. He has a 28ft single engine cat, not a 22 single or a 28-32 twin.

i totally understand the concept of not wanting to spend a boat load of money and using parts you already have but i don,t think the op understood what cp told him.as i posted earlier his engine will be a decent runner with the stock hp500 heads&cam BUT no way will it compare to the engine with a good set of aftermarket heads&cam properly sized for marine use.and nobody wants to have problems with their freshly built engine.no matter the direction he goes the proper tuneup including a fuel system that can handle the engines demand is vital or it can fail.all i am saying is a good set of aftermarket heads&cam will absolutly make more power than his stock parts will and anybody that thinks otherwise is either confused or in denial.

HP500, Dart Pro 1 heads, 525 EFI cam, 250 Blower shop blower kit.

I can get heads and a cam but I have that 420 mega blower and chiller that I am going to use. I got rid of the 250 mega. Would aluminum heads be better especially cause of weight. Who would be a good place to get that 525 cam

the 420&chiller will work nicely.

So a 525efi cam. Can i use the same heads that I have

Also I was gonna run 2 750 holleys from my previous 250 mega setup . will those be enough if i richen them up

They will work. No need to "richen" them up necessarily.

If you went with new good flowing heads, cam, chillers, they might be on the borderline being a bit small CFM wise. With the stock heads, I think you'll be just fine with those carbs.

Will you be dyno tuning these engines?

No the motor is in the boat didn't want to pull it . I'm pulling the heads off though wanted to have them rebuilt . That is why I wanted to get a cam since upper end would be off . If I decide to use these heads should I change anything on them for better Flo or lift etc?