His boat had riser blocks...thus why I think it didn't.

It's all about the gravity.

496HO manifolds and tubular risers workout?

I am curious as to the cam and would it fall off too early after looking at the graphs....

Maybe a single plane intake would help out?

It shouldn't fall off too early, however, if you want more power you'll have to break out a wad more cash.

Cam, lifters (for higher lift) , Roller Rockers, ValveSprings, Pushrods.............

How about the freeze plugs ?? Are they brass or SS ?? If not one of the 2 might want to change them.. Head gaskets will prob be ok. Run the exhaust valves a little on the loose side.. And yes might want to use a marine style carb with the looped vent..


John jr

And when you think that wad of cash is big enough, grab some more. Wish I had come across a deal like this when my 454 bit the dust a couple years ago. Would have saved me a LOT of money. Should run similarly to a 502 Mag. Depending on your intentions for the boat, might make a nice package. If you are worried about reversion, look for a used Mag cam in the Swap Shop. Should be pretty much a bolt-in swap.

Freeze plugs are brass. I bought the engine.

What carb would y'all recommend?

Stick with the gmpp dual plane intake?

Do a search on in this section for ZZ502 modifications to marine use and/or Kidnova username search. He and I both have done the ZZ502 motor. And to your question on the intake, NO. Throw that crap in the scrap bin. Single plane--4150 based intake of your brand choice. I found the HP950 Holley worked very good. Before you guys all say that it is too big, it is NOT. That carb is really a high velocity 750-800 carb.

Changed out the oil filter bypasses as mentioned.

I'll look at single planes today. Dart? Victor jr? Something else? I'm only looking to run up to 5-5200 rpms

Spacer?

Thanks for the help so far.

I like the edelbrock rpm air gaps myself. I had a 540 ci with a tunnel ram single dominator (wasn't my choice) and ran until i could not stand how much fuel it used. I put ann rpm air gap and a 950 and there was a 100rpm difference at wide open throttle