GT40p swap, E7 springs and rockers?

Sep 22, 2005
170
0
16
29
Vancouver, BC
#1
Hey Folks, I'm going to be starting my gt40p swap in the next couple months. I'm swapping my E7s with a pair of remanufactured P heads, a tubular gt40 intake, and retaining the stock cam.

The heads came with springs and stamped rockers, presumably stock gt40p pieces. I know these springs should be replaced, even with an HO cam, so I want to use my stock E7 springs and rockers on the P heads. My next big-money uprgrade down the road will be a cam, springs, rockers, and quarterhorse tuner, since I can't afford a cam and tuning equipment now I'll do all of these in my next "wave" of mods. With all that, I have a few questions for you guys:

1. Are the stock E7 springs and rockers better than the stock GT40p springs and rockers?

2. Are the stock E7 springs and rockers a direct swap onto the GT40p heads?

3. If 1 and 2 are a yes, is there any reason E7 springs and rockers should NOT be used on gt40p heads with a stock cam?

Thanks :nice:
 
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hollywoodstang

Active Member
May 23, 2006
1,095
1
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#2
Here is my advice, and what i prefer doing it right.

For next couple of months, Drive the car with E7 heads, for those couple of months, Save money for springs and whatever ratio and brand rockers you are gonna buy, DO IT ALL AT ONCE.

You do not want to use E7 or the "P" springs, You can get the beehive springs from crane for $150 as a package and it come with retainers and locks too, and you dont have to machine the heads, It's just drop in.

Crane also makes the rockers, you can get it in 1.6 or the 1.7 ratio, they run about $250 for the energizer cast aluminum version which is more then enough for pedestal street motor.

So later on when you wanna do the cam swap, you don't have to worry about other stuff then.

Good luck dude :)
 

Zero_chance

Founding Member
May 29, 2001
1,236
5
49
37
Maricopa, AZ
#3
Though Hollywoods advice probably isnt what you were looking for, its actually very sound advice. I know youre probably anxious to get the new stuff on like everyone gets with new parts, but it'd be much easier to change it over with the heads off instead of trying to change valve springs with the heads on the car. You do it that way you run the risk of dropping a valve into the cylinder and then you have to yank everything off again... Pain. And trust me, I know about the itch to throw parts on. I have a turbo kit and all the related parts sitting in my shop and I have to wait until July.. :rolleyes:
 
Dec 23, 2002
574
2
19
38
Ogden, UT
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#4
"Holy thread from the past batman"
My question to anyone is: will the stock e7te springs be "ok" on the gt40p's if; i am going to stay with the same cam for my engines lifespan?
My .444 stock cam is best for a turbo build. So there is no reason at all to ever switch my cam.
 
Dec 5, 2006
107
1
18
55
St. Louis Mo.
#5
I did a P head swap last year and got a .540 lift spring kit from Alexs. I no longer see the kit on the web site, but they have kits on sale and it is what I paid as well. You would be better served being patient and put $ away for the kit. I pulled 2 sets of bone yard heads from Exploders in St. Louis and did my own mild porting and clean up, then I took them to a shop out here in AZ when I moved and they further cleaned, painted milled and installed the spring kit for 200.00. It was a PITA to get my headers to fit cause I had to ding and "massage" #4 and #7 tube and used an Acell shorty plug on one of them, but it runs sweet, no problems in over 4000 miles..Hope it works out for you, here's the link. I had questions and they got back to me via email promptly too.

https://www.alexsparts.com/on-sale-...e-springs-kit-hyd-roller-560-lift-vsk7i49-r5/
 
Dec 23, 2002
574
2
19
38
Ogden, UT
Visit site
#6
I did a P head swap last year and got a .540 lift spring kit from Alexs. I no longer see the kit on the web site, but they have kits on sale and it is what I paid as well. You would be better served being patient and put $ away for the kit. I pulled 2 sets of bone yard heads from Exploders in St. Louis and did my own mild porting and clean up, then I took them to a shop out here in AZ when I moved and they further cleaned, painted milled and installed the spring kit for 200.00. It was a PITA to get my headers to fit cause I had to ding and "massage" #4 and #7 tube and used an Acell shorty plug on one of them, but it runs sweet, no problems in over 4000 miles..Hope it works out for you, here's the link. I had questions and they got back to me via email promptly too.

https://www.alexsparts.com/on-sale-...e-springs-kit-hyd-roller-560-lift-vsk7i49-r5/
May i ask, are you running an aftermarket cam? I remember seeing the .540 lift springs at alexparts. Initially thats what i wanted to do. After e-mailing them a couple of times they replied with the ".440 to .500 lift springs" would be my best option going turbo. I asked about using the .440 to .520 lift and they replied:

"Carlos,
Our previous suggestion is still the best choice for what you are doing. The 520" will not perform as well when used with a turbo as boost pushes on the backside of the intake valve so it needs more pressure to help keep the intake valves closed under boost."

The confusing part tho, is that (if memory serves me right) stock springs had a .500 lift? Perhaps im wrong about that?
 
Dec 5, 2006
107
1
18
55
St. Louis Mo.
#7
Don't know which way to point you as far as boosting, I would keep searching advice to back up their statement. My 95 has a Comp Cam stage 1 with .512 lift with 1:6 rockers. I think stock lift on GT cam is like .440 something, and if you are going to use the stock cam while boosting, perhaps that is why they are recommending those springs. I used to run the Steeda 19 in my 94 as I was told it would work well with boost, but sold it before that dream could come true.
 

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