Which pair of these heads should I use?

[351Coupe]

So I've ended up with a pair of D0OE 351w heads, and a set of GT40P heads. The 351w heads came off the motor in my 68 when I put the TFS heads on. The plan was to use those on the 302 in my 90, but I recently pretty much stole a set of F77E GT40P's.

I'm not really sure which heads I want to go on the 90. If I use the GT40P heads, I can re-use my beehive springs and roller rockers from my E7's. But then I have to find a set of headers too. I've also been told I can keep my headers and use 90 degree plug boots.

If I use the 69 351w heads, I'll either have to use the stock stamped rockers or buy new ones.


They both have the a 1.84 intake valve (vs E7's 1.78), but the the P heads have the same size exhaust valve as the E7 (1.46) while the 351w head has a 1.54 exhaust. It looks like I would gain compression with the 351w head also.

I wonder which one has the better chamber design? Some say GT40P's.

Any experts want to chime in?

Thanks!

[thesource]

Is there any work done to the older heads? Stock for stock, the P head is probably going to perform slightly better. I would make sure you mill either set of heads to increase the compression ratio of the engine to around 10-1. Compression really helps in a N/A mild street engine.

[Damnittsteve]

screw the p heads, you wont have to buy special heads for the 351w heads.

[Turbosvo]

I have 69 Windsor heads or my car and I ran pretty good with them!

[Magnimike1]

Shouldnt have a problem with either if running longtubes.

[stevo]

Everything I have read says the gt40 heads are the best flowing stock iron production small block heads.

Stevo

[351Coupe]

Well a couple of exhaust valves got bent in the ported E7's I had on the car so I took them off and put the GT40P's on tonight. I'll finish it up this weekend and see how it runs.

Oh, I did have them milled also, and re used my roller rockers, but not the beehive springs (I suspect a couple of them to be weak, causing the valves to float).

I wonder what kind of RPM those stock springs are good for.

[bobs94formula]

I'd replace the stock springs ASAP, just for added insurance.

[sickpony]

E7 heads are a lot better than people make them out to be. IMO I would recommend them over reg gt 40's. 351 heads are cool for 20 years ago. I have been really impressed with GT40p heads. Ford racing shorty headers are not that expensive ( its not the plug wire but the plug that is a b). Gt10p and cam ftw. You have to use the hex end of your spark plug socket and an open end wrench to do a plug change but no thermactor holes to fill to delete smog.

[351Coupe]

I got it going with the P heads Sunday. Now I'm just fighting a little issue of the two big wiring harness connectors. The car will miss until I wiggle them around, then it will run fine for a little while.

I'm about to go and clean them with electronic contact cleaner and put some dielectric grease in them, hopefully that will clear it up.

[10sec302]

E7 heads are a lot better than people make them out to be. IMO I would recommend them over reg gt 40's. 351 heads are cool for 20 years ago. I have been really impressed with GT40p heads. Ford racing shorty headers are not that expensive ( its not the plug wire but the plug that is a b). Gt10p and cam ftw. You have to use the hex end of your spark plug socket and an open end wrench to do a plug change but no thermactor holes to fill to delete smog.

You must not get out much.

[Snatch Napkin]

I got it going with the P heads Sunday. Now I'm just fighting a little issue of the two big wiring harness connectors. The car will miss until I wiggle them around, then it will run fine for a little while.

I'm about to go and clean them with electronic contact cleaner and put some dielectric grease in them, hopefully that will clear it up.

I take it you're talking about the 'salt and pepper' looking plugs.
This has been a long time issue for fox bodies. There is a way to increase the contact of the pins, but you will want to be very patient.
I'm on my phone right now, but when I get to work I'll copy a link with decent directions.

Basically, you'll spread the male pins open a little so they'll fit in the female side better.

[Snatch Napkin]

That last post was pre-caffeine.

I just remembered that I was supposed to do this when I got to work.

http://webpages.charter.net/darrell1/mustang_efi.html

10 Pin Connector modification:

1. Take the 10 pin connectors apart (salt and pepper shakers).

2. use a pick like tool to spread the male terminals open more so they make better contact. In the center of each male terminal there is a small seam and seams down the sides of the terminal which allows you to spread them open.

3. Apply some dielectric grease to the terminals

4. Plug the connectors back in.

[351Coupe]

I cleaned them and put dielectric grease on them last night, problem solved. I think I've heard about spreading the pins before but I didn't even think about. I may do that if it ever gives me problems again.

[Txstang1]

I have a set of brand new comp beehive springs if you need them. $50.00. They have only been installed and Then removed after one or two start ups. Also have a brand set of fms roller lifters , same story on those.