Daryn

iTrader: (19)

valve will be fuged ... i have some 317's and some 853's .... can i use a int or exh valve from that? are they the same size? (2.00), (1.55)

Jason 98 TA

iTrader: (4)

Sorry to hear. That's always one of the biggest problems with a single spring. You always run the risk of killing parts if a spring dies.

If you decide to go double springs give us a call, our new EHT spring or newly updated .660" LS spring kit will work very well for you & have tons of R&D to make sure they can stand up to YEARS & YEARS of use & abuse!

01ssreda4

iTrader: (96)

Thats why I went with PAC beehives. So far so good.

adam1803

iTrader: (65)

As long as the valve sizes are the same you can use them, but you'll have to have a machine shop match up the seat and valve so it seals right.

99blancoSS

iTrader: (115)

PAC 1218 and 1518's are direct drop in replacements, no seat or seal changes needed to run them.

Nothing wrong with a single spring if its a good one. Comp has had nothing but issues since switching to a different MFG for their springs. PAC on the other hand has not had issue with breakage at all.

OR as Jason suggested their new double spring is a nice piece and will come with all you need to install them as well and it wont break the bank doing so either. PAC has a nice premium double spring as well called the 1521 but it's $200 more than the PRC. It features nitriding and Nano peen processing.

Daryn

iTrader: (19)

i have a new set of crane duals that came off the car. only problem is a lost a retainer and i have to find another one that will fit... prc retainer should eh?

lovescamaros28

Comp 921 springs

99blancoSS

iTrader: (115)

PAC 1221 would be my choice over the Comp. and the 1521 would be the best of that spring.

PAC used to make springs for Comp. Comp switched and the breakage has been an issue since then. It was supposed to have been corrected. But it's all about the batch number.. LOL why nother with that crap when you can have the PAC spring instead ?

PAC makes them for a lot of companies, OEM and aftermarket, IIRC Ferrea being one of them.

The PRC is an option as well and less money than the PAC.

Damian

iTrader: (89)

When did Comp switch from PAC? Because the Comp 941 singles were notorious for breaking 8-10 years ago, back when I'm sure they were still affiliated with PAC.

I personally have never had a problem with 918's, and I've installed TONS of them.

OP, can you give us details? Which 918's were these? Blue stripes or the newer aluminum looking finish? How many miles on the setup? Cam lift? etc

JFM-jr

iTrader: (23)

Given the conditions we sometimes force these parts to live in **** can break.

35th SS

iTrader: (2)

everytime I read one of these thread the more I get paranoid about changing to a dual spring on my 35th.running the comp. 918s forgot which ones already.theyve been awhile in there.

adam1803

iTrader: (65)

I wasn't referring to the springs, the OP asked if he could use a used valve from another set of heads he has.

BlackScreaminMachine

iTrader: (17)

I would weigh them, odds are they should be the same. Also check the guides, they maybe fucked too. Magnafluxing the piston would be advised too. You can buy a DIY'er kit from Eastwood.

99blancoSS

iTrader: (115)

Got to be 2- 3 summers ago now.... was a bit of news for a few months and then it died down for a bit.