those are them,,and I don't know why crane would list a weaker spring,,but then again,hyd rolers used to have 120-130lbs seat pressure.I never went that low,but some did at 1 time.

If anything I'd rather run a little more spring even though some might argue due to premature lobe wear but screw that. (Within reason) I relate to a roller coaster ride and rather stay on track than bouncing off the rails. Lol.. regardless thanks for posting.

What is your installed height with the new heads and valves and stuff?

[QUOTE=sutphen 30;4537410]those are them,,and I don't know why crane would list a weaker spring,,but then again,hyd rollers used to have

John, compare your cam card to the Master Crane Spring Catalog part# 99876 and you will find those specs should put you more at ease.

good choice too, little more aggressive than the Crane 99876 but less than the Crane 99885

but I think the OP wants the original spring for the 900sc

I haven't cked in with Jim v in a while but I was assuming around the 1.90/1.95. I certainly like the price of the cranes better. Just being honest. Lol. Seems like springs shot up in price. I understsnd you get what you pay for but like lifters there's a lot private labaling with springs. I'm trying to think of what the other spring that's been discussed lately that many seem to like. That cam card still gets me with said pressures at recommended installed height.

How many hours before replacement with the pacs and nexteks?

Not sure where the other spring pressure recommendations came from, but fwiw

#148631 Crane 254/262 .636/.636 solid roller calls for 190/488 spring pressures. Same for 138791 cam, 138641 which is a 262/270 just like below,

#138131 , is a 262/270, .714 lift cam. This calls for 230/648 spring pressures.

As you can see, the #138641, and 138131, both have the exact same .050 numbers, and 114LSA. One requires 190/488, the other, 230/648. The lobe profile on the 138131, is MUCH more aggressive , than the 636 lift cam. Not all solids require the same spring pressures. The lobe profile dictates that. The 138131, while has more lift , also has way shorter advertised duration.

I do not know who made the cams for the 900sc.

Joe I sent you a copy of that cam card I think for your simulator software a while back. That came with cams I bought. Almost identacle to the replacement cams sutphen30 has used from bullet. In regards to bullets lobe vs cranes I am not sure. I would only guess bullets might be a little more aggressive in which case I would imagine would require more spring pressure. I do believe the 900's cam come from crane. I have two of them in hand that came from Dennis r.

Comp cams 955-16

Seat load 240lb @ 2.0"
Open 608lb @ 1.3"
Spring rate 526lb/in
Coil bind 1.23

This is what I've been running for 3 years going on 4 now. No troubles at all and these motors run hard all the time. I put in a new set every spring. We usually put on 75 to 100hrs in a season. I probably wouldn't replace them but its cheap insurance. I took a spring to the machine after a season of running and the keywest poker run and it didn't differ much from the initial install, comp said these springs should get 100hrs no problem .