Ford guys don't need no stinkin' cheby parts! Ford has enough junk to go around! Not that I am against using Ford parts but in the case of a cam with more than .5" valve lift get a good set of roller rockers - not just roller tips. (I am using roller tip rockers on my 351W - it is a grocery getter with 350 hp but valve lift is less than .490")
Alright, some more questions. I was lookin around for some used heads that are fairly cheap and heres what ive found. -1966 289 Hi-Po Heads C60E 54cc 1.67/1.45 Valves With Screw In Studs And Guide Plates -GT40 heads off of a 93 cobra -stock E7TE heads My question is, which of these heads will handle .520 lift after I install the proper valvesprings, and which set is the best performer?
Personally I would rework the GT40s, but almost any stock, iron head needs port work to have flow increases above .500" valve lift. And the GT40s and E7s use pedistal rocker arms, so for your .520 cam you should change that, too. The later heads have relativley big chambers, might require milling. By time you finish all the machine work, porting, and parts buying you could buy a set of aftermarket aluminum heads that are designed much better.
The C9 and D0 351W heads have smaller chambers, bigger valves and ports and You can find them complete in the wrecking yards for cheap. They will not allow you to turn a 351W to 7000 rpm but they will support a 302 at 6000! All you need to do is a good valve grind and screw-in studs. (the more "massaging" the more you get out of them.)
The stock pedestal rockers are physically not big enough for a high lift cam, not enough range of motion. You need to get roller rockers or convert to stud-mount rockers.
I'm with BMc. You'll eat up $800 reworking a set of stocker iron heads. A couple hundred more will buy you a set of aftermarket aluminums that will be ready to run and outperform the stockers. Oh yeah, and you'll save 40 lbs off the front of the car.
The prices that I have seen for complete - ready to run after-market heads is well over $1000. It's closer to $2000 for complete heads. For $1200 you can get the bare heads and then buy the valves, springs, retainers, locks, rockers, etc. Maybe you have a better source than I.
My Edelbrock Performer RPMs listed below cost $1069 delivered and I added a set of Scorpion roller rockers for $190. They come complete with stainless valves, 3-angle valve job, guide plates, screw-in studs, springs for up to a .570 lift cam, and the ports are gasket matched. I even got a "free" Edelbrock jacket with 'em.
Both Summit and Jeg's sells assembled Edelbrock Performer RPM heads for $1110 plus shipping. Patriot Performance sells their assembled heads direct to you for $795 plus shipping. These heads flow 244/183 at .500 and have springs good for .579 lift.
Paul is right. Either use what you got. OR If you want the best iron possible, get the early W heads. OR Save up and get the aftermarket. Don't spend dough for heads that are no better than each other or what you already got. Get something for your dough and find the proper Ws or get aluminum.
Those are not the "Hi-Po" heads if they have 1.67/1.45 valves... Standard '65 & up 289s had 1.78/1.45 valves, and the "Hi-Po" edition had larger than that...
I suppose I will nit-pick those heads a little too. I think someone is trying to talk those heads up as valueable by playing the "HiPo" card. The valve size is wrong for K-code heads. K heads didn't have guide plates. They had 'guide slots' where the pushrod passed through the head. Regular heads have big round holes that you don't really pay attention to. K heads have tiny narrow rectangular slots where those big round holes normally are. Can't miss it when you look for it. Also they say you cannot run guide plates with those heads because the guides tend to compete with each other and throw your geometry for a loop.
