can you make a set of oval ports into rectangle ports are you able to do this?

I don't think you can get the ports that big but you can enlarge them and port match them to a rec. port intake.
Why not just get the heads you want instead of spending the $ on your heads.

I agree with Tinker. To take a set of oval ports and port them out to almost a rectangle port would be good for power and JimV could definately do that for you, BUT like Tinker said; you would be better off buying a set of heads that are already close to what need and THEN have JimV tweek them in for you from there. Because taking oval port heads and having them ported out to somewhere near a rectangle port head is A LOT OF PORTING WORK which will cost BIG $$$ vs buying a set of heads like some Merlin oval port heads (or whatever) that will be closer to what your engine will like and having JimV clean them up for you. That would probably be the smarter thing to do. Hope this has helped a little. Have fun.

so kaama is it woth the money to get alum or is it worth 20 hp or so i am at the point where i need to buy pistons got a 540 n/a kinda at a stoping point till i figure out what heads

carreraboat,

Not sure I understand your last post. You are saying that you have a 540 cubic inch engine with oval port heads---right? If that is so, then I would say "yes" you would definately bennefit from a larger port volume head. Even a aluminum head like the AFR CNC ported 315cc heads would wake that thing up by as much 80hp perhaps. "Bad to the Bone" is a member here on OSO and he has a 35' Cig with a pair of 540's and he went from stock GM rectangle port heads that had some port work done to them to the AFR aluminum 315cc CNC ported heads and he said it really woke his engines up! He said everywhere throughout the RPM range he said it was very impressive!

So to answer your question "yes" you will definately see more than 20hp and you DON'T have to even go with the aluminum AFR's CNC heads to get it either!

What heads are best for a 454 mag? Everything else is stock. I'm thinking of head work and a cam.

The AFR 315cc heads would be too large for a nauturally aspirated 454 as would pretty much any rectangle port head, where as the oval port designed heads will give much better torque and throttle response. The GM oval port head comes the stock valve size of 2.06" intake valve and a 1.72" exhaust valve which can be modified to the larger 2.19" intake valves and the 1.88" exhaust valves, and a Merlin Oval port is even better. Actually, the Merlin oval port is a much nicer set-up than the GM oval port. If you have the GM oval port "peanut port" heads I am quite sure they have the hardend seats in them. Another one of the old GM oval port heads is the "049" casting of which do NOT have hardend seats and they would need to be installed. No matter what heads you go with I would still install bronze valve guides or bronze wall valve guides. The Merlin's already come with really good air flow, larger valves and hardend seats right out of the box!!! All you would really need to do is have some minor bowl/pocket areas cleaned up which would tweek in the air flow even better. A friend of mine has 454's with the Merlin oval port heads, dual plane intakes, hyd flat tappet cams, Holley 800 carbs, stock Merc ignition and his made 505hp @5500rpm and 514ft.lbs of torque on Tom Earhart's dyno! ----he bought the boat from someone else and he's not even sure if the heads were cleaned up in the ports or not!---but he was still happy with those results!

WOW, I would be too.
We are going to be up at Grand Haven for labor day weekend. Will you be around?
I want to get figured out what to do for my next winter project.

Mark

Payton, I will probably be boating out of Muskegon during the Labor Day weekend and will buzz down to Grand Haven for the races.....I'm quite sure I'll run into you-----I'm sure I will see a bunch of you guys there!