dean campbell

looking for advice on replacing the original GM iron heads with aluminum ones to go under some whipple chargers on a couple 502’s. i know dustin recommends dart pro one heads, what is everyone else’s opinion? i would like to reduce the compression ratio to about 8.2:1. any recommendations on who could put something like this together? looking for a builder who has good experience with blown applications, that won’t charge me an arm and a leg.

Turbojack

I have ordered some AFR 335CNC's. Going to put on procharged 540 when they get here. They had the best numbers when I ran them on desktop dyno with my setup. We will see.

RLW

My friend, JpClear of OSO, has ordered a pair of Canfields for his 540. Same thing that Keith Eickert uses on his engines.

bobl

Dean, you'll get a ton of answers on this one, and they'll all probably be correct. I just did a Whipple with the 2000 CFM throttle body on a 454 Magnum with mildly worked Brodix BB1 heads, a mild cam and high performance exhaust. It made 789 hp on the dyno at 5500 RPM. I think the Pro 1's are the best right out of the box. The more important thing is to get the correct runner size and chamber size to fit your application. I run ported BB2+ heads on my NA 555 and it makes over 600 HP with MPI and a very mild cam. I've also heard good things about the Canfield heads. Whatever you go with, make sure you have them assembled by a good shop to marine specs and get the inconel valves.

Bob

cobra marty

Edelbrocks CNC Victor marine heads are worth a look.

jdnca1

Dart Pro 1's are tough to beat for the $$$.

29scarab

While were talking about this.

I have 96 502mpi with a Whipple on it.

It has zero gap rings, crane HP gold roller rockers.

Can the stock MPI intake flow enough air to feed the Pro 1's?

If not what ,modifications would need to take place?
If it can flow enough would the stock injectors be big enough to flow enough fuel to the engine or would I have to buy bigger ones?

How much are the heads?

I'm looking to maybe spend a little money this winter.

Thanks

jpclear

I think that the AFR probably builds the very best but as is usually the case with the very best, you must pay. I would call Dave Kubert there, 818-890-0490. He is extremely easy to talk to and knowledgable and accomodating. Tell him what you have and they can custom build them for you. I would also contact Ken at Canfield Heads, 330-533-7092. He is very good too. Canfields have flow #'s that are close to AFR's for considerably less $. To see the #'s yourself, check Chevy High Performance magazine website @ www.chevyhiperformance.com Good hunting. --- Jer

Turbojack

Before I ordered the AFR I researched all of the heads. From what I was being told was after I bought some other heads I would need to take to someone & have them port them so they would really flow. I was getting prices from $600-$900 to port them. I could not get a solid number. So by the time I bought them from AFR I was not spending any more $ that if I had them ported. Once the hassel factor is added by messing with someone that can screw up your heads I thought the price for the AFR were about equal.

Whipple Charged

If I had to pick a head for the 700-800hp level, supercharged, best bang for the buck I feel are the Dart Pro Ones, 325 intake runner, 119 combustion chamber. I think they run just above $2000 from Summit fully assembled. The CNC 335's are incredible and are still worth the money, but there quite more. Brodix makes awesome heads as well, but are more expensive, more room for porting though. I've only heard about the AFR's, I know the small block heads work really well, I have to imagine the BB's work well too, but can't say from experiance. Never tried the Canfields so I can't say. If your looking for some people to do these mods on your motor, try GT Performance, 909.982.8391 or Paul Phaff Racing Engines, 714.894.7573.

29Scarab, no problem feeding the heads on your engine. You'll need a bit more fuel on top and a smaller pulley to increase airflow to see the gain, but it will be fun, especially torque, acceleration is unreal. Typically, for this application, I would get the out of the box Pro 1's (119/325), run a 3/8" smaller pulley, will have about 8lbs. of boost and should pickup another 75-90hp. Stock injectors are fine, would raise fuel pressure 2-4lbs. with an adjustable regulator and leave intake as is. You can cut the runners off to increase flow, but seriously, they'll flow plenty as is.

I'm interested in what anybody finds out on the heads though, would love to hear some numbers from some who have run the AFR heads. I would stay away from the Edelbrock heads for either of these applications, I've never had any big numbers from those.

Thanks,
Dustin