Pictures - up pipe and valve spring cups

[mblum]

Yes, those shims will work with the stock cylinder heads.

1.250" OD X .814" ID X what ever thickness you decide to use.

 

[Fikse7]

I did Comp 980 springs without cups and I used shims that brought them to 1.697" seated. Your shooting for 1.7" so you can get the spring pressure up to its listed seat pressure of 92 at 1.7". Can't remember exactly but I wanna say I used .030 shims under the springs or else the springs are 1.667" installed by themselves and the pressure is way lower than rated. I think it drops down to the like 84psi at 1.667" rather than 92 pounds seated pressure at 1.7". Its best to buy a set for 8 cylinders and have a shop pressure match a 6 cylinder set for you. That is all I can say to that.

Joe,

Trying to understand this in my simple mind, but wouldn't the height be greater without the shims? Without the .030 shims, it would be 1.697 + .030 = 1.727??
Am I understanding this correctly? Also, using shims for reduced installed height = more seat pressure?