Somebody is always selling Ps on eBay. Shock tower mods aren't needed. The problem is the location of the spark plugs. They are a little bit lower and stick out almost straight instead of being angled up and to the side like normal Windsor heads. On the driver's side, mine are actually under the header tubes. The passenger side isn't a problem because of the way the header tubes sweep rearward away from the plugs. As described in other threads I used Accel shorty plugs and 90* electronic distributor cap terminal and boots to connect the plug wires to the plugs. Some grinding was needed on the header flanges for plug socket clearance. Of course all this depends on what headers you're using. To change plugs I have to loosen the headers and use a cut-down socket. The Accel plugs are expensive, almost $12 dollars apiece, but they are double platinum so you can go for many thousands of miles without touching them. Some have modified their headers to fit so none of these problems occur. I didn't take that route because I had just had my headers Jet-Hot coated and didn't want to mess them up. Some people are of the opinion that the heads are not worth the trouble, I believe they are.
bmcdaniel, I saw somewhere where someone asked about using flange spacers between the headers and GT40P heads. In your opinion, would this alleviate any of the spark plug problem whit the heads? It may cause a clearance problem with the headers and the towers, but that is a solvable.
How much would you say a decent set of stock heads is worth, just curious, cause i work at a part store, and we can get reman'd e7's for about 130(my price) a piece? would this be worth it or should i just find a junkyard, or save up for something better?
flange spacers I guess it depends how much extra room you need with a particular set of headers. By using shorter plugs, terminals and boots I reduced the overall length of each by 3/4". That would be an awful thick spacer plate, but a 3/8" spacer might keep you from having to buy the expensive plugs. Would probably still need the small 90* terminals and boots. Might make it easier to remove and install plugs, too.
BTW, if you look at the flow figures vs. valve sizes in Maverikrick's post above you see the P head exhaust flows about 20% more than the E7 with the same size valve, and even outflows the GT40 which has a larger valve. Just goes to show you can't always just put larger valves in a head and get the best flow. Port size and shape are big factors. The values he posted are at .500" lift. For a street engine you want to pay particular attention to the mid-lift figures, .200" - .400". That's where the valve spends the majority of it's time during opening and closing. It's handy when you can compare flow rates on a graph and see the total area "under the curve" for each head. That provides a good representation of total flow for each rather than just looking at peak values. Hope all that rambling made sense.
Is anybody going to answer MountainMav regarding his $130 price on E7s. I would pay that for remanufactured heads in a second, unless told that junkyard heads would be as good. It seems that remanufactured would have all the new seals and such. Mountain Are those reman E7s complete with springs and lifters and all that jazz? I would buy from HiLo if I could find them at that kind of price, just to know that I don't have to have them worked on (except for some cutting away at that smog bump everyone is talking about).
$130 each sounds fair enough to me.As far as the "smog bump" all you want to do is lay a header gasket on the head,trace out the port holes and then port 'em to match the gasket.With this one mod my car picked up 2.5 tenths in the 1/8(9.05 to 8.79)nothing else was changed.....well before the 600 holley worked great,after the porting it wasn't enough so I ran a 700 dp and it liked it.The carb was a bit much I know but I ran nitrous some and didn't want it going lean.BTW,best bottle pass w/stock heads was 7.81,the solinoids started messing up(NOS stuff)so I never got a clean pass w/the ported heads on spray.(just so you didn't think I ran hi-8's on bottle )
Is porting something I can do in the garage using "pencil" grinders and such, or is it strictly machine shop? What if I have a Bridgeport milling machine? Still too difficult?
It's not difficult to do yourself. I've done several sets. Don't get too greedy hogging out the ports, especially for a street motor. You want to keep good velocity (air speed) in the ports. You don't want to radically change the shape of a port unless you have access to a flow bench to know if what you are doing is beneficial or not. The major items are to port match to the intake and headers. Always have a smaller port feed into a larger. In other words, the intake manifold ports should be just slightly smaller in width and height than the head's intake ports. The head's exhaust port should be slightly smaller than the header openings. Think of it as funneling the gasses into the next section. Get rid of any ridges or casting marks in the intake runner but leave the surface rough to promote fuel atomization. The exhaust runner likes a smoother surface for less turbulance. Do not change the shape of the short side radius (floor) of either runner where it connects the valve bowl with the runner, you want to keep a nice gentle curve, gasses don't like to take sharp turns. That's why aftermarket heads with raised exhaust ports work so well. Open up and smooth the bowl areas above the valves and streamline the valve guides. If you have P heads be careful around the exhaust valve guide, it has a water jacket around it. Other Windsor heads are solid and you can cut the guide way back. Open up as much of the exhaust runner as you can to the same size as the port opening. Get rid of any thermactor bump in the roof. P heads have a crater instead of a bump. when you open up from the port roof to the highest point of the crater you remove a lot of material from the roof. The gasses like that. If the heads you have need a valve job, get a good three-angle. If you need new valves, get some that are back-cut at the stem. If the heads have good valves and valve seats be careful you don't nick the seats when your porting, tape up the seats. You can use an air die grinder or an electric. Some places on the internet that discuss porting say you can't use a "hobby" type grinder. I have a 20 year old Black and Decker electric hand grinder that works just fine. I buy Dremel abrasives at Wal Mart. Depending on how much you grind expect to spend 30 - 40 hours to do a pair of heads.
They will bolt up but you will have to work through some plug clearance issues on some of the later heads.
hey bmcdaniel that web site is AWESOME.....and just in time for me...since i am going to try the porting on my heads this week and weekend... thank you so much
Depending on how much you plan on doing/spending on a set of stock heads, if its much at all, i go with the FORD SBF ALUMINUM HEADS Y303,GT 40,GT40 you found on ebay I have more in my gt40p heads then you can buy them Y303 heads for If i had it over to do again i bought a set of aluminumn and been done with it and cheaper. Just my Jim
