I have the 7K3's on my 400/461 build and they are really good for the price. Mine were free with the 72 400 from the local scrap yard. Already had 7/16" studs with polylocks. I cleaned the bowl area, ported and did a gasket match and filled the exhaust crossovers with molten aluminum. They work and sound great. I have the forged Sealed power pistons at zero deck so my compression is about 9.5. I use 93 octane and have a 2802 cam to keep the detonation away. BTW, pulls like a freight train! I also drilled and tapped the end holes for headers and inserted a 3/8" stud. Took about 1/2 hour on the drill press and is why these heads are so cheap. They match the higher regarded 96's except for the header flange bolts needing to be tapped and a stud installed. With 4 tube headers and the exhaust crossovers filled it cleans up the muddy exhaust note that Pontiacs have versus Fords or Chevy's.
I forgot to add when I had my heads reworked with new valves, the machine shop had to install hardened valve seats. Apparently these are the last Pontiac heads without hardened valve seats.
Thanx for the reply Bill. I really appreciate it!! Didn't know about the missing stud on the end holes. Also didn't know about the '72's being the last year for hardened seats. I will have to ask him about that.
How do you 0 deck a block? Do you machine it down the .025 or what ever the deck height is? Does is mess up the fit of the intake? Or can you do it with slightly longer rods?
That is what is so great about this forum. If you got a question, someone has been there done that and can offer some advice.
I have a set of 7K3s on a 455. Although, my heads didn't have enough meat to drill and tap for the outer exhaust holes for the headers (apparently some castings had the machined surface but no hole and others don't have the surface at all), so I made some angle brackets with studs that mount in the holes on end of the heads. I had seen parts for sale to do this but was much cheaper to make my own.
I know that washing and waxing my car with the present condtion of my paint is like polishing a turd.....but it's my turd and I want it polished!
Mine didnt have the pads either and is why I used a stud. That way there are two clamping sets of threads for the headers. I got about 4 threads of engagement on the threads on the head. Spotts Performance used to sell the header brackets for about $100 a pair.
the machine shop zero decked the block after finally getting the crank, rods and pistons all balanced and correct. They assembled the short block and measured how deep in the hole the piston were and milled the block to achieve zero dwon in the hiole for better compresion, quench and detonation resistance. No problems with the heads or intake that they told me about.
Spotts Performance used to sell the header brackets for about $100 a pair.
Yeah, I remember it was some stupid price for the parts. I used some pieces of a 1" x 1" angle iron I had laying around and 4 bolts from the hardaware store. Cost me less than $2.00!
I know that washing and waxing my car with the present condtion of my paint is like polishing a turd.....but it's my turd and I want it polished!
Daryl did you notice any performance benefits when you put them on? I am going from a pair of 4X's 114 cc chamber, I am hoping this will help quite a bit. Do you have a picture of your bracket you made?
The 7K3 heads were on the engine when I bought the car, so I don't have anything to compare against. I do however run all day long on pump gas with no problems without having to severly retard timing
I'll look through my photos on my computer here at work to see if I have one of the bracket, if not, I'll take one and post it this weekend.
**No pic on my work computer. I'll take one at home and post it.**
Last edited by daryl_keys; 10/05/1203:57 PM.
I know that washing and waxing my car with the present condtion of my paint is like polishing a turd.....but it's my turd and I want it polished!
Here's a link to the Spotts Performance brackets. It's better than a photo I can send because my headers are installed. IMHO, not worth anywhere near $69.00. Notice the note saying if you have the pad, the brackets won't fit.
They say with the cast iron manifolds, you don't need the outer bolts. However with headers, you definitely need them. The gaskets are the same. It's just a matter of using the hole or not.
I know that washing and waxing my car with the present condtion of my paint is like polishing a turd.....but it's my turd and I want it polished!
OK Thanx for the info Bronze Bird. It would make sense that after a certain amount of head milling the intake would need to be milled/cut too.
I have decided with the 7K3's missing the outer most head exhaust stud I will keep looking for a set of 6X-4's or my all time favourite edelbrocks at a reduced price. i can wait for a used set. the car smokes the tires at will now with the 455 with the 4X's.
Any luck with your sale? I noticed it was over a year ago you put 'er up for sale (at a very good price i thought)