LT1 springs

[873.8Turbo]

I am going to put LT1 valve springs in my car. I was told not to use the cups , but should I put shims or spacers?

Also- my car has new lifters in it(not done by me) and wondering if i have the stock cam. Is there anyway to tell if it is the stock cam?( i dont want to pull it out of the block but everything else is out

any of your opinions would be appreciated

 

[blackbuick87]

Dont use the late model LT1 valve springs from the Camaro, they are too stiff and will wipe a lobe. You want LT-1 valve springs from a 70's 350.

Or better yet for $40 get a set of Comp Cams 979's to avoid confusion

 

[Steve Wood]

Even the early models are too stiff at close to 100#.

Use the 979s with the cups or the 980s without.

 

[49-blues]

wouldnt this all matter on which cam is being run? stock or aftermarket.

 

[873.8Turbo]

yes I do have the correct LT-1 springs from GM

 

[6SENSE]

With much help from Bob Kolhouse (87LtdT) I just went through the valve spring decision making process fiasco. Bob had some in depth info and testing on the various springs for our cars. I was forced into getting into this stuff more than I wanted to, but if I hadnt I would not be very happy right now.
I believe the 979s would be Comp Cams recommended replacement for our cars, and are a good choice. If you want a little bump up go with the 980s, that is what I went with. They gave me a seat pressure of right around 90 (springs that came out were only in the mid 60s) with the proper shimming to get them to the correct install height. If your car is stock as far as cam and heads (unlike mine) I dont think you should have to worry much about shimming. You shouldnt have any trouble with being in the 1.7" install height range.
The more I researched, the LT-1s seemed a little stronger than needed. 90lbs is more than enough. Some guys go with 80. I would try to stay under 100lbs for sure, which is where the LT-1s are at if I remember correctly.

 

[Steve Wood]

Originally posted by 49-blues
wouldnt this all matter on which cam is being run? stock or aftermarket.

Why would not you run the springs suggested by the cam manufacturer if you run an aftermarket cam?

Comp lists 980s for some pretty good cams.

Due to the problem with #3 exhaust, primarily, it is somewhat unwise to run significantly stronger springs than required, imo, for any given cam including the stock one.

 

[49-blues]

whats the seat pressure for the cc979 s?

 

[6SENSE]

Originally posted by 49-blues
whats the seat pressure for the cc979 s?

Advertised load is 80 lbs @ 1.700" .
The cc980 is advertised at 91 lbs and the LT-1 is advertised at 104 lbs.
(info thanks to Bob aka 87LtdT)

 

[49-blues]

thanks