01FbTaWs6

iTrader: (12)

OK guys, what diameter valve spring shims do we use? The spring OD is 1.290, but they dont make a 1.290 OD shim. So I would assume we use the 1.250 shims, but just wanted to post up here to make sure.

01ssreda4

iTrader: (96)

Stock spring or double spring? I just bought some from some store called Alex's parts on ebay. He list them as stated for LS1 engines.

01FbTaWs6

iTrader: (12)

PAC 1518 beehive springs

01FbTaWs6

iTrader: (12)

and his are 1.255 OD, so 1.25 OD will work just fine. And they come in .030, I need a bigger variety then that, as I doubt that just .030 thick shims will get me to where I need to be. Im shimming them .030-.040 from coil bind. I dont have the heads back yet to know forsure what thickness of shims I need, so i was going to order the pack that comes with .015, .030 and .060 shims from summit.

ebk06

iTrader: (5)

I have the exact springs and i was wondering the same thing. Hopefully someone will answer for us.

vettenuts

iTrader: (4)

Comp makes them in 0.015", 0.030" and 0.060" as 16 part kits or you can guy all thickness' as a kit.

01FbTaWs6

iTrader: (12)

vette nuts, I know that. If you read up there, I posted that was what I was going to do. What i am asking is, WHICH DIAMETER? I am assuming the 1.250 will work fine.

ebk06

iTrader: (5)

I still think you need the bigger diameter so the spring will actually sit on the shims not around them. But im not sure if the next size up (1.33 I think?) will fit in the cup?

01FbTaWs6

iTrader: (12)

i only found 1.25, 1.437 (I think) and 1.50

vettenuts

iTrader: (4)

Anything larger then 1.250" will not fit into the pocket machined into the head. I have used these on several heads, including stock 241's. Here is their old catalog.

01FbTaWs6

iTrader: (12)

perfect! Thanks man!!

vettenuts

iTrader: (4)

Just for background, even though the spring is 1.29" you have to subtract the thickness of the wire (approximate) because the wire is round. So you don't need a shim the exact diameter of the spring itself. Hope that makes sense.

Ictinik

How are these springs holding up? I was thinking about getting a set.

when I bought my car the owner said he had $1800 in the head.. stage2 port and polish (LE) and springs..should I assume that he used good springs? or install these..I will be putting in a Lunati 60122 in a couple weeks

TurboBuick6

iTrader: (2)

You need 1.250" OD shims. The springs should not sit on the shims themselves either, they should be on a seat/cup. The shims go underneath the seat.

vettenuts

iTrader: (4)

Unless you have the one piece GM seat/seal, then they go on top of the seat/seal. The shims from Comp are also hardened.