brodix bb0 would be ok.

 

Brodix BB-2x 340's have worked fine for me.

 

At 6500rpm, ideally, it's going to want a fairly large cross section...somewhere around 3.5"sq., and a big int. valve. Don't get too distracted by port volumes...they're really irrelevant as to the size of the port. I think the Darts will work butmore importantly, have them flowed to get the actual numbers, and have the cam made accordingly.

 

360cc toplines(now rhs heads) work good on a 598..i am turning my 85 back into a real street car..9.1 comp,solid roller with a 598 bottom end.

 

598, i would look into the bb3 xtras, 355 darts, 357 afr's with a sniper jr intake may even go to the std sniper intake. with 10.5 - 11 to 1 and setup right you could have 850+ easy..

 

if you want closer to 900hp the head hunters, rfd victors, the new sniper heads darrin morgan just designed..

 

I had a boat a few years back and I found you really can't bog them down, I would go with the Brodix Head Hunter and don't look back. You know how human nature is, we always want to go faster. You need to buy the bigger head now so you don't outgrow them. There is alot of builders claiming 850-900 hp with them on pump gas motors. You can also call Curtis and he will help you pick a head even if you don't buy them from him, he is one of the nicest people you will talk to.

 

We have a 565" blown/injected alcohol motor that makes more HP than I can use (in an open boat, we're not allowed to go quicker than 7.70's or faster than 145 MPH, depending on the association). No need for this new motor to ever get set on kill. This is just a lake hot rod because the blown/injected deal is just to hairball to play with. Again, durabilty is really important, but we still want it to run decent.
Lots of good info and thanks for all the replys.

 

Before you buy anything talk to Curtis Boggs at RFD, hes doing some bad ass stuff with conventional heads and can get you the castings too, if you need them.

 

Thanks Chris. Been reading up on the pump gas 555 Mike Lewis did and Bogg's name came up a lot in that thread. I'll definitely talk to Curtis before I write a check.

 

Just remember it is a 598 not a 540, that 4.600 bore likes a little bit larger head. You also need to remember that you will be cruising at 3000 plus rpm and you don't want it to lay over at 6000.

 

I would also call Curtis Boggs. See what he says. You can call Brodix direct they also can help. Just a lake boat I would look at BB3X.

 

I'm more hardcore than most. My choice would be the big cheif style heads. You could use less intake lobe and have it be more driveable, while still making good power with room to grow later.

 

David,

I build a BUNCH of marine heads, .. ( grew up on the water ), .. there's a hand full of options you have, ..
I can build you something on one of the Edelbrock castings, I have a few programs that would be perfect, ..
I can build something on a Brodix casting, .. or you can look at the Brodix head Hunter series, .. I don't think I'd look much past that.

I'm a brodix dealer and would be glad to help you, but as most know it's hard to get through on our phone
till after we move the shop. So call Brodix and Talk to Mark and if you have questions they don't answer I'll help you all I can.

Curtis