I spent some time reading the old posts and have come up with a few choices for a spring that would accomodate 540 lift.
Isky 235
Crane 10308
Comp 987
1215 Beehive not sure the PAC number
Also one old post showed the LS6 springs...but no real evidence of that working.
The cam I saw was an AI cam 208/ 221 525/540 112LSA....with 1.6 rr
It looks like a high lift ZZ4, so questions are
1.Is there enough seated pressure to run the Isky 235 spring for this cam? If not, is the 987 too much spring for this cam, on a stock weight valves and lifters, with Pro Mag rockers.
2. Is 550" lift the point where NSA rockers should be used or is 540 too close?

 

Don't mess around: Crane Kit #10308 with the 99893 springs or call Crane and ask them which kit contains the newer version 99892 (good to .750 lift.JMHO

 

comp 987s FTW!

 

If you can get the spec sheet for that cam, it will tell you which springs they recommend and at which ht.installed. You can use NSA RRs anytime. I believe it's more a matter of RPM than lift. SAs will work just fine if you want to go that way. The 99893 spring will handle your cam very nicely. As mentioned, the kit # is 10308.

 

Ok, so the Crane 10308 kit will have either set of springs and will have enough pressure to handle that lift. Do you think that they will be able to keep their pressure up over lets say the next year or so, putting 10 - 12k.
And Bubba....you would rule out the Isky 235s....correct?

 

The Crane Kit 10308-1 has includes the spring 99893 only. The 99892 apparently doesn't come in a kit---probably the 10308 would work, but you'd probably have to order the 99892 instead of the 99893 which comes with that Kit. Having said this about that----don't concern yourself with the 99892 spring. The 99893 spring is a very popular spring and should fit your needs.

Eventually any spring will lose some strength over time and use, but I seriously doubt that this spring or others would peter out that soon.

 

I'm sure Pac 1220s will fit the bill to but If its an AI cam why not ask Ron/Phil for a recommendation

 

What he said, asking a bunch of people what springs to run when they aren't valvetrain experts or know anything about the lobes of the cam is just asking for trouble.