My valve springs are binding . . . questions on new ones!

[Zero Signal]

I've finally confirmed that my GT40 valve springs are going to bind. I got the solid lifter in at zero lash and as I suspected, there's nothing left of the spring. I couldn't even get the .015" feeler gage in between the coils. We had to shim the springs originally to get any kind of seat pressure but hell, even the seat pressure isn't enough to hold compression right now So the stock springs are going in the trash.

My cam sheet said that the Comp Cams 986 springs were required. So I looked those up at Summit and it turns out they're double springs.

My question is, will the stock spring retainers work on these things? I have a feeling they won't. I was also looking at this kit that comes with retainers. Will the 375# open pressure be too much?

 

[Rick 91GT]

They do require new retainers, I used those springs years ago on a GT40 cast head. You may find you need more installed height, you could use a +.050 lock or retainer combo.

What is the current installed height that you have now?

 

[Zero Signal]

I don't have a good measure of it without the height micrometer. I hate to spend $40 on one. My intalled height right now is lower becuase the springs are shimmed. I know I will be ok with new springs and no shims. BUT if I could figure out where to get a seat height mic. for cheaper I might get one and go from there.

Then the question is, which retainers do I want? Would summit have them?

OR is there a way to measure it without the micrometer?? I might just opt for the second kit there. Unless they seem too heavy for my use. I won't be taking it over 6k so I shouldn't a crazy spring, but if I could run the recommended spring for my cam, I should be golden.

 

[Rick 91GT]

Height is very important, maybe you can borrow one from someone local or if they are off the car take and have it measured at a shop.

The height will verify what retainer and or locks you need so you use the spring correctly without coil bid issues. I know on the GT-40's we had I had 2 different retainers on it to ge the proper settings.

 

[Zero Signal]

So are you basicly just trying to match the seat height to the springs specified seat height to maintain the proper seat pressure? Or just trying to prevent coil bind? Thanks for the help

 

[RIO5.0]

John....Just a thought...Send a PM to Mike, Thumper...He does up gt40s..

He installed Vassco double springs on my heads and I use the stock retainers...I'm E7s though...Just a thought...Sounds like your getting into more than you bargained for...Why can't things be simple...
Looking at the "instructions" on your Summit link for the kit, It appears some in depth measuring needs to be done?? Is that a 302/GT40 P/N for the kit...