I'm not going to point fingers but saying that pro 1 heads are notorious for a problem with out explaining what the root problem is is worthless on here. Our little community is built up of people who can relate personal experience and can tell of the solution to remedy the problem. I think we all appreciate everybody's opinion but mix some facts to back up your statement. Saying the pro 1 heads are notorious for problems: worthless. Saying that pro 1 heads need a longer stud that is 1.3" to prevent rocker stub breakage and that the stud protrudes past the boss into the head along with providing a part number specific for the application: priceless

is there a valve cover that clears stud girdles and clears marine exhausts?

The Dart pro 1 head was designed to be a light weight head. They come in around 29lbs each. There race series come in around 45lbs each. Where did all the weight go. Maybe someone used there magical wand combined with a sprinkle of pixie dust. I don't think advising the OP to take a look at the stud bosses is bad advice. If you feel as though it's not a good idea to pay attention to this area of a cylinder head then don't pay attention to it. I've seen problems with intake and exhaust bosses with these heads. Was it a geometry issue? There is always a geometry issue its the nature of the beast and BBC's have the worst of them all. I've even seen a few sets of Pro 1's where alot of extra effort was put into the stud bosses to try and combat issues before they happen.

The 598 is getting AFR 357 CNC heads with Jesel pro shaft rockers. And timing belt.

Lunch is over - back to tearing the Daytona apart.

ok, this seems like backwards land. the race series is 16 lbs heavier than the pro 1? why make it that much lighter if not to win races? when the race length is april to october and the winner is the one who spent the least time in the pits, one would think durability matters more than the boat being 32 lbs lighter.

Thanx for pointing that out Joe, something I would not have checked.

Correct stud on bottom for my Dart heads. Top is what the previous owner installed. "it`s fiiiiine"

http://33outlaw.zenfolio.com/img/s10...63852700-3.jpg

The dart race series, are a completely different casting, than the Pro 1's. The Race series weigh 37lbs, where the pro 1's , weight 29 lbs. Thats actually 8 lbs, not 16lbs. While AFR doesnt publish their heads weights, I believe if you put one on the scale, they are around 32 lbs..

There is nothing wrong with the pro 1 casting. They have been used by many many offshore engine builders, many other forms of motorsport builders, sold by hardin marine, keith eickert, cp, and many other marine shops, as well as thousands of shops across the country. If their was a flaw in that casting, it would have been corrected a long time ago. These are not procomp heads we are talking about.

Thank you for the correction. I was going off of memory. 8lbs of cast aluminum is alot of aluminum. If you go and put big roller springs on these heads the potential for failure goes up. There are also limits with the deck of the head but I don't think you will find it with pump gas and a blower.

i ran 355 cnc pro1 heads on a blown alcohol engine with 340 lbs on the seat,8500 every pass,guess what,never had a problem.as i said,ATTENTION TO DETAIL!black baja,care to tell us exactly what problems YOU have had with a pro1 head.