f_inscreenname

I like the OE heads but like said you have to put some time into them. This past winter I picked a bare set of 990’s for like 500 bucks on ebay. I lucked out. Besides them having some surface orange (it wasn’t even rust) they were fresh from a performance shop. Ported and polished super nice.
It was kind of a letdown in a way. I’ve been collection spring seat cutters, seal seat cutters and porting and polishing tools from the last couple head jobs I’ve had to do. I was ready to make them the nicest set of heads we ever owned. At least I got to use the stuff on some fine tuning of the heads and port and polishing the intake and exhaust.
My point is, if you are building a motor. You can use pretty much any heads you want (within reason).
I have a set of 049’s on a shelf. Come to find out they were 123cc when they were supposed to be 113 so you have to keep that in mind. The way to fix it is use the right pistons. Just like my 990 heads, I use .210 dome pistons which gives me about 10.25 to 1.
If it was me and I wanted to leave the door open for future upgrades I would look for a set of O/E square port, open chamber heads with 1.880 / 2.190 valves or bigger. Your valve springs will have to match your cam so you are building/rebuilding something anyway. Once you have your heads and know the chamber cc then you can get pistons that will get the compression number you are looking for.

Budman II

iTrader: (1)

I built a 489 a couple years ago and went with the AFR 265 ovals, as Haxby suggested. Went with partial CNC, upgraded to inconel exhaust valves, I think I was all in for around $2200 shipped. You could definitely finde these all day for less than $2500, unless prices have gone up. If you are worried about corrosion at all, AFR will hard anodize them for you to help protect against corrosion, but if you boat in salt or backish water, I would go closed cooling.

I ran a fairly mild hyd roller and a Dart single plane oval intake and the motor dyno'ed at 585 HP and 605 ft/lb torque. Torque band was very flat, it made upwards of 600 ft/lbs from a little over 3000 RPM all that way through 4500 RPM. These heads could EASILY support 600+ HP with a more aggressive cam. Keep in mind that the Dart intake and stock Holley 800 CFM carb that I used were probably limiting factors for power production.

You could probably run your oval port Air Gap with these heads and make a boatload of torque, but a single plane would probably work better if your cam is fairly aggressive. You could port match the intake to the "roval" shape of the intake ports on the heads fairly easily. I left out this step on mine, so there is some additional power that you could pick up. No matter what heads you buy, if you purchase them fully assembled, it would be prudent to take them to a good machine shop and have them checked out - pay particular attention to valve guide clearance, as they can be a little tight for a performance marine environment.

98scarab

I have purchased the teague custom marine stage 1 cam hydrllic roller
intake lift duration centerline
cam lift .3450 226.0 107
valve lift .5865 226.0 107
exhaust
cam lift .3590 234.0 117
valve lift .6103 234.0 117

98scarab

Also the boat is a fresh water only boat. Thanks for all the information guys it is very helpful

sutphen 30

you got the crane 731 cam .

Budman II

iTrader: (1)

I would think that a cam with those specs would work very well with something like the AFR 265 or something similar.

MILD THUNDER

iTrader: (3)

Actually , the 731 crane is 226/236, @ .050..But whats interesting, is it looks like

their stage 1 is the 139011 crane
http://crane.carshopinc.com/product_...d/76045/139011

, stage 2 is the 139021 crane,
http://crane.carshopinc.com/product_.../153302/139661

stage 3 is the 139651,
http://crane.carshopinc.com/product_...d/16124/139651

and stage 4 is the 139661
http://crane.carshopinc.com/product_.../153302/139661



looks like Teagues camshafts come from this place. Possible they took the crane designs, and had someone else grind them for them.

http://www.andrewsproducts.com/autom...ing-capability

http://teaguecustommarine.com/em0011...nufacturer=867

98scarab

The cam card says by. Andrews Products.