E7 head to GT40P head swap help

[Timmy390]

So everyone knows by now the issues with my 351W build. If not, long story short cracked E7 head. It's FUBAR

Looking to go with some GT40P heads as I already have headers (Bronco Hut shorties) that will work with P heads.

So my questions are around the rebuild and swapping them onto my 351W

Current setup
96 351W 20 over sourced from an E350 61-64cc chambers
Stock E7 heads milled 20 thousands (stock rockers, springs, pushrods)
Stock rollers, lifters and cam (Explorer/Truck cam not HO)

1. Will stock form GT40P head (bolt holes drilled for 351W) bolt up and be OK with the stock cam, lifters and pushrods mentioned above? I've been reading (and that's a bad thing) I need different pushrods?

2. IF I wanted to upgrade the springs to handle the HO cam or even the Cobra cam, what spring kit should I be buying?

3. Do all the upgraded spring kits have the correct locks (something about the exhaust valve rotating) for the stock valves?

Tim

 

[sykanr0ng]

From my own research these are the springs:

http://www.alexsparts.com/sb-ford-gt40p-drop-in-valve-springs-kit-hyd-roller-580-lift/

 

[Timmy390]

Found a few sets of GT40P's at the yard just 10 minutes ago. CHEAP........

So looks like I'm going to go with them. Not open on weekends so that's a problem....

Tim

 

[Timmy390]

From my own research these are the springs:

http://www.alexsparts.com/sb-ford-gt40p-drop-in-valve-springs-kit-hyd-roller-580-lift/

Thanks, that kit is one of the ones I found as well.

Tim

 

[Teal68]

Hopefully someone else will confirm, but best I remember you will have to enlarge the head bolt holes. Not a big deal though.

Springs...I always say get springs to match the cam. Period. You could at minimum see what the cam will require and have a machine shop check your existing springs pressure to see if they will work. My bet is they will not have enough pressure for the increased lift. Leave the stock cam and you are probably good to go.

Push rods....if you swap the cam I'm pretty confident you will need shorter push rods. Otherwise I think you'll be fine with what you have.

So I know I don't sound too confident in all that advise, but here is one thing I'm sure of...Syk is right, Alex part's is the place to get your springs and keepers. Excellent reputation and very knowledgeable. I bet they could answer your questions with certainty!

 

[Timmy390]

Hopefully someone else will confirm, but best I remember you will have to enlarge the head bolt holes. Not a big deal though.

Springs...I always say get springs to match the cam. Period. You could at minimum see what the cam will require and have a machine shop check your existing springs pressure to see if they will work. My bet is they will not have enough pressure for the increased lift. Leave the stock cam and you are probably good to go.

Push rods....if you swap the cam I'm pretty confident you will need shorter push rods. Otherwise I think you'll be fine with what you have.

So I know I don't sound too confident in all that advise, but here is one thing I'm sure of...Syk is right, Alex part's is the place to get your springs and keepers. Excellent reputation and very knowledgeable. I bet they could answer your questions with certainty!

Yeah, I'm going to email Alex Part's and see what they say. I'm not swapping the cam right now (cost and I want my rig back on the road ASAP) but was looking to upgrade the springs while having the heads rebuilt so I would be halfway to there but the upgrades might not work with my stock Explorer/Truck cam per the notes on their site.

If I get the heads I have my eyes on, their from a 2001 Mountaineer.

Tim

 

[sykanr0ng]

The GT40 and especially GT40P valve springs are barely enough for the Explorer cam.

I would replace them even with the stock cam.

Marginal when new plus 15 to 20 years use and sitting?
Springs take a set after a while.

 

[barronj]

How much are you spending for the heads, the bolt hole enlargement and the new springs + install on the springs? Since they'll be at the machine shop, are you having a valve job done on them? What's the total cost to get them from the yard, to picking them up from the machine shop ready to install? How much are the specialty headers running as well?

In short, how painful is it going to be to go to the P head as a solution?

Not including gaskets and fluids, just the hardware I asked about. Sorry for your engine woes.

 

[Nickm1024cobra]

How much are you spending for the heads, the bolt hole enlargement and the new springs + install on the springs? Since they'll be at the machine shop, are you having a valve job done on them? What's the total cost to get them from the yard, to picking them up from the machine shop ready to install? How much are the specialty headers running as well?

In short, how painful is it going to be to go to the P head as a solution?

Not including gaskets and fluids, just the hardware I asked about. Sorry for your engine woes.

I was in a similar situation. I found that after modifying the p heads I was better off getting a set of aluminum heads. I went with gt40x heads. Did that for a couple reasons.

Quality aluminum head, but not up to par with a AFR or Trick flow. Because of that I found them reasonably priced second hand on the mustang forums. They are also pedestal mount rockers, so no need to swap pushrods or rockers. Got a set shipped to me for 400 bucks off another forum. Might want to consider it.

 

[barronj]

I was in a similar situation. I found that after modifying the p heads I was better off getting a set of aluminum heads. I went with gt40x heads. Did that for a couple reasons.

Quality aluminum head, but not up to par with a AFR or Trick flow. Because of that I found them reasonably priced second hand on the mustang forums. They are also pedestal mount rockers, so no need to swap pushrods or rockers. Got a set shipped to me for 400 bucks off another forum. Might want to consider it.

That's where I was headed. I would never replace irons with more irons, when the aftermarket has gobs of used heads with decent springs in them already.

One aluminum head mfr I really like is edelbrock because they do something not everyone else does, and that's put helicoils in their bolt holes. Makes cross threading in to the aluminum a thing of the past. Getting bolts started in the headers where there's not a ton of room for your fingers, you're trying not to chingle the header gasket, etc, it's easy to get a bolt cross threaded on aluminum heads. I use studs on either end of the header to get it lined up and all bolts started. In the end, I use studs on the valve covers and studs on the intake. I buy them from the bolt supply, they aren't expensive, and the clamping force is better with studs than bolts. Not that additional clamping force is necessary, but it's not to the detriment, or a negative trade off for the decision to go studs.

 

[Rox Crusher]

I went with P heads because they were cheap ($100) and readily available.

My machine shop bill for enlarging the holes, valve job, and shaving for 9.5:1 compression was 650 +\-.

In hindsight I would have been better off getting some AFR heads as they would offer the additional benefit of running cooler.

 

[barronj]

I went with P heads because they were cheap ($100) and readily available.

My machine shop bill for enlarging the holes, valve job, and shaving for 9.5:1 compression was 650 +\-.

In hindsight I would have been better off getting some AFR heads as they would offer the additional benefit of running cooler.

And more horsepower. I got lucky when I was building my mill, it was in 2008-2009, when things were looking grim, and parts were selling at a steep discount. I found a new set of AFR 185's for $800 that had a rough time in shipping, and the studs from one head pitted the surface of the other head, so I milled them 10 or 20 thousandths to fix that. I don't recall. I just know that she won't run without 93 octane (diesels after shut off with anything lower than premium, but that's a compression issue more than anything).

 

[Timmy390]

Already have the headers
The pair of GT40P's off a 2001 Mountaineer $70

Because of all the trouble, the machine shop is going to build them for basically for free. I'm paying for parts but no labor.

Alex Parts's spring kit with seals and shims $160
New Valves $100
Guides $25
Seats $40

So say $400 invested in them there bouts but will no know for sure until I get them from the yard.

Tim

 

[barronj]

http://forums.corral.net/forums/windsor-engine-parts/2277713-gt40x-heads-illinois.html

 

[AZ69EB]

The machine shop should help with spring upgrade Or call Comp Cams or Trick Flow for new springs, retainers, and locks.

If money issue. P's are an upgrade over E7's. Low RPM's you will not notice much difference. As the rpm's go up is when you really notice the difference in flow rate, especially with good after market heads.

They will bolt on without any pushrod changes. But, it's always good to measure. Again, should help you verify due to your past history with them.

If you decide to change cam, then it is more likely to have to buy new pushrods. Keep stock rockers as pedestal mount is no fun to set up a new valve train. Not worth the effort or money with stock build. IMO
Hope this ends your issues and your back on the trails soon. Good luck anday your nightmare end and you fun begins.

 

[Timmy390]

They will bolt on without any pushrod changes. But, it's always good to measure. Again, should help you verify due to your past history with them.

Hope this ends your issues and your back on the trails soon. Good luck anday your nightmare end and you fun begins.

Great news about the pushrods.......

The first thing the machine shop said when they saw the pic of the leak was "we will make the right".

Thanks and I hope this ends my nightmare too. We're basically starting over with an inspection of the block and new/rebuilt heads. The engine ran strong and I'm very happy with the performance of it (what little I did drive it). The only reason I was looking at the GT40's is I'm already running the GT40 upper and lower intakes. Figured this would just complete the GT40 upper end.

I could just grab a E7 from the yard and have it built but if I'm going to pull one head why not just grab 2 GT40P's and have them both built.

Tim

 

[bronconut73]

Great news about the pushrods.......

The first thing the machine shop said when they saw the pic of the leak was "we will make the right".

Thanks and I hope this ends my nightmare too. We're basically starting over with an inspection of the block and new/rebuilt heads. The engine ran strong and I'm very happy with the performance of it (what little I did drive it). The only reason I was looking at the GT40's is I'm already running the GT40 upper and lower intakes. Figured this would just complete the GT40 upper end.

I could just grab a E7 from the yard and have it built but if I'm going to pull one head why not just grab 2 GT40P's and have them both built.

Tim

Agreed Tim!

Your threads continue to be fun and educational.

Looking forward to this one too.

 

[barronj]

I could just grab a E7 from the yard and have it built but if I'm going to pull one head why not just grab 2 GT40P's and have them both built.
Tim

You're replacing the intake gaskets regardless and they usually sell header gaskets in sets, so it's an extra head gasket, a few more bolts, and more HP with the P heads. Don't use the FelPro 1250's when reinstalling the lower intake. Too many threads about them failing when used as a long term intake gasket.

Many people re-use stock head bolts, but they are not designed to be re-used, since they are what's called a torque-to-yield bolt, meaning they stretch a bit when first torqued down. If you aren't already running ARP bolts, invest in them.

I mentioned that I use studs in the head's outside bolt holes to help minimize headache when getting the header bolts started; I also use them on the 4 corners of the intake so that when I lay my bead of silicone down on either end rail and set the intake down, as well as any silicone I've put around the water jacket ports, it doesn't get mashed out of functionality when you set the intake down and start trying to line up your bolt holes.

Hope you get back on the road without any further mess.

 

[Timmy390]

Many people re-use stock head bolts, but they are not designed to be re-used, since they are what's called a torque-to-yield bolt, meaning they stretch a bit when first torqued down. If you aren't already running ARP bolts, invest in them.

Yes, I already have ARP bolts.

Tim