Thinking about making the plunge over winter. Looking at http://www.krepower.com/Pontiac%20Aluminum%20D-port%20Cylinder%20Heads.htm. Any comments would be welcome.

Very nice and I was eyeballing them for my 455 build. But it came down to cost at the end and I could get the Edelbrock heads a bit cheaper.

It's not fast enough?

Not very pump gas friendly. Don't even like to boot it with pump gas. Aluminum heads seem to be the answer for a few things. But it does come with a price!

Dished pistions, rings and a re balance can be had for cheaper than a set of heads.

We are talking about a 428 with dished pistons

I am going with the 74cc alum haeads when I do my rebuild. Already talked with Jeff Kauffman about my 400 and got a plan now with a custom grind comp cam to fit the bill. Jeff really knows what he is talking about, so shot him an email or call him and he can answer all your questions.

I got 'em. They're awesome. Don't know if they're better than the E'brocks, but you sure get alot more input from Kaufmann. They'll help you put the build together, not just sell you a set of heads.

Also, consider contacting SD Performance. I sent my Kaufmann's there for CnC porting and chamber cleanup.

I have them on my 428, 83cc chambers with flat top pistons and roller cam. I like them. I also had Dave at SD port them and shape the heads he also port matched the intake, I matched the exhaust. Mine is 10.5:1 ratio with zero deck. Seems to run ok with lots of quench and an efficient heart shaped combustion chamber.
The only concern I had was the bolt threads are not heli-coiled, but I had no problems with that. I don't know if the Edelbrock ones are or not.

Just a question about sending the KRE heads to SD, why would you send them there to get ported when you could get that done where you bought them? I am assuming you bought them from KRE, Tin indian or some other place who sells the KRE heads and also ports them, if not my apologies. Was it cheaper to use SD?

I bought the heads and intake from Dave, he matched them while he was porting. He's done gobs of heads and has CNC programs for many chambers. He gets the bare heads and machines to his/your specs.

I changed my build after spinning a bearing. Decided to go "all out" on the re-build...already had the KRE heads.

Choosing between the two, Edelbrock of KRE.
The decision should be made on what you want for flow, charge velocity, chamber shape, intake, camshaft, etc. The two heads are not the same. When I bought mine the Edelbrocks had larger port volume than the KREs. I wanted a higher velocity flow as I was building a rather mild street/road car not a race car and was looking for good low RPM response so I went with the KREs and a rather mild camshaft. I wanted an engine that got most of the power at rather low RPM and mine straight lines at just over 5000 all the way to 6000+ but gives me over 600 lb/ft of torque under 4000 RPM and 400+ at 2000 RPM. Lots of low RPM grunt but the power levels off at just over 5000 RPM. If you're building an engine for max power at high RPM you need different heads, intake and camshaft than one built for low RPM torque.
My heads flow 310/239. If I was building a different engine with a larger cam and intake Dave would have ported the heads to a higher flow.
I don't think one head is any better than the other just saying choose a head and the machining to suite your needs.

Good advice. Port volume should be an essential part of your decision in planning and picking the head that best suits your wants. Last winter I picked up a set of older Ehead round ports. They had been previously worked so I'm not sure how big they are now. Out of the box they were advertised at 215cc. They are probably more than that now. I replaced my 16 iron heads on my 400 and they killed my low end. I didn't know about the "lazy" air charge due to the port size. Apparently they would require a much bigger cid to get the full potential from them. Don't get me wrong, they still run fine but for a 98% street car it can be sort of disappointing when you can't spin the tires at will like you could before. Planning and knowing is everything before you buy.

Al, flow is 310/239 at what lift? Runner cc? CID of motor? What cam?

Lift is at .55", runner cc is 204 ported up from the 197ccs, at 28".
Heads and block received an ultra fine grind for better sealing.
I'll attach the engine spec sheet.
Flow on spec sheet is advertised, actual is 310/239.
Chamber volume is 83 not 85.
I changed from the rope gasket to a two piece teflon lip/chevron rear seal.
The oil pump is not a high volume, melling only makes one for Pontiac.
It took me quite a while to build due to machining problems, mains where bored three times, I had to polish the seal area of the crank and I had to make a tool to machine the rear seal groove.
My wife was happy to see it out of the garage so she could park her car inside again.

I sold the ram air III heads that were on the 428 when I bought the car to a fellow who has a later low C/R 400, they will work better for him than they did for me.

Bob
This is another internet myth, there's hundreds of smaller cubic engines with 250cc + ports that will rip your head off when you step on the pedal. I know I built a few. It all comes to proper camshaft and carburetor and tuning.

I don't think anyone said the larger volume ports won't work with a particular CID. One has to match the camshaft and induction system. I don't think putting 250cc port heads on a factory stock 350, 326 or 428 will net good results.

Chief, if there was a way to make these heads work on this motor I'd sure like to know how. I went from a 406 with cleaned up 16 heads, a 226/226 cam with lots of overlap, long branch mans and tons of low end torque to that same 406 with ported round port Edelbrocks that flow 300cfm @.600, a 230/230 roller cam and Doug's headers and my low end tanked. So much so that I'm seriously considering go back to the iron heads and just cam it up a bit and save the heads for a bigger motor.

Throw that cam in the garbage. There's far better choices. Even a custom grind to do what you want to do.

Seems to me you're working blind trying to choose a camshaft without knowing all the parameters of your build including port volume and head flow. How many camshafts do you want to buy using the trial and error method? Getting all or as much information possible before you start switching out camshafts is paramount. Info such as: bore; stroke; piston dish/dome; piston type/weight/design; deck clearance; compression ratio; rod length; rocker type/ratio; valve size; chamber volume/shape; head heat; CID; intake type, runner length/dia; port volume/length/average diameter; header primary length/dia; muffler type; tail pipe dia; carburetor or fuel injection type and size; intended use. Once you obtain the info choosing a camshaft is simpler.

Myth or not I believe charge velocity is the important point when buying and/or porting heads. The more air an engine uses the more power it can produce. Porting a set of heads for large cc values will result in the potential for more airflow but if the same porting results in slower flow performance will drop at lower rpm. If an engine can use X cfm of air at any rpm that's all it will use even if the heads can supply 2X cfm. Volumetric efficiency is maintained by good air velocity. If you have good flowing heads supplying all the air the engine needs then increase the port size, while leaving the rest of the engine the same, the larger volume port will result in a slower moving charge. Bigger isn't always better.
Heads are ported to the needs of a particular engine, not all engines are the same and heads ported for one engine may not necessarily work on a second engine with different specs.

Then there's always the fear, and I hope not, that the person who ported your heads screwed them up royally. Anyone can buy a die grinder and have at a set of heads, that doesn't mean he/she knows what they're doing. I have grinders and have ported a few but Dave has ported an untold amount of heads and has developed CNC programs for Pontiac heads and aluminium aftermarket heads, there's no way I would have done as good a job as he did, so it was worth the money. I'm sure you will get yours working well once you find out what was done to them and get the corresponding camshaft.

Back to Glider's question,
The aluminium heads may be what you need for your detonation problems. As Ordy and Bronze bird say, phone them and discuss what you have and what you want, I'm sure they will lead you in the correct direction. Just remember they boast some pretty good numbers for out of the box performance but they are not on a stock engine and you are probably wanting some street manners not just the highest HP number you can obtain. High HP numbers on the dyno are nice but you still have to drive your car on the street, unless your's is for drag racing only.

Respectfully,
Al

Thanks for all the good reading. I have improved on my tune since I started this thread. This is where I am if I want to upgrade. Winter is coming so we will see.