OK, here's what I have...
Edelbrock "roval" alum heads.
Crane Hydraulic Roller Cam 234/242 @.50 and .610/.632 lift

The recommended Crane springs are the #99896's
O.D. is 1.540...seat pressure is 146#@1.875 height....Open pressure is 452#@1.225...coil bind is 1.085"

The springs that are on my heads(came with) are Edelbrock #5745's
O.D. is 1.550...seat pressure is 125#@1.975 height...Open pressure is 310#@1.475...coil bind is 1.160"

Is there anyway I can use the springs that came with my heads or is it too much of a stretch? I checked Summit and the Cranes will run me $189.00.
Is there any other springs I can use that I can just swap out(no machining)?
All help appreciated!

Anybody?
Anybody?

Bueller...Bueller...

Silver,
The only one that can give you the correct answer on this is the camshaft manufacturer. The rest of us can all guess from previous experience, but there are so many forces in play with valve springs that it is not worth guessing. Open and closed pressures are only part of the equation. There are harmonics involved that you would not believe. I have seen valve springs go crazy and stop making power in a particular rpm band and then settle down and keep on working up to 8000 rpm. You just never know.
Call Crane on Monday and ask them...they will tell you if the springs will work or not. If not, they can tell you what you can use.

Silver,

Here is what you have: Crane 99896 is a 470 #/inch spring rate and the Edle 5745 is a 370 #/inch spring rate. And so the Crane is definately a much stouter spring.

Now assuming (which you SHOULDN'T do before you make a decision) that your actual installed height is 1.975 like your spring suggests here are the numbers:

Installed Height: 1.975"
Max. Lift: - .632"
Open Height: 1.343"
#5745 Coil Bind: - 1.160"
Clearance= .183"
Minimun Clearance to CB: .060"
Available amount to shim: .123"

New Installed Height: 1.855"
New Open Height: 1.223"

Pressure @ 1.855" = 169#
Pressure @ 1.223" = 403#

So again if your heads have an actual installed height of 1.975" and you shimed your springs .120" your seat pressure will be a little higher than what Crane calls for, which wouldn't be horrible. And the open pressure would be shy by 49# or 11%. Again not terrible, but in my opinion you will be really pushing these springs. I would expect a shorter life span for these springs than the correct Crane's. You will have to decide for yourself if you can afford the better springs vs. the potential life span reducition and performance loss.

Hopefully some folks with more experience with springs can offer another opinion.(Edit: Looks like BillK just gave you a good opinion. :D )

Good Luck.

.

I ran springs that were only a little lite on my SB.
It never made a sound as far a float goes.
It did stop reving at 5800, so I knew something was up. Well I didn't get to it soon enough. I only went to 5800 maybe 10 times. Lazy me. It started chewing up my spring shims and put hardened steel in my oil.
The easy part was the hour I spent scraping metal flakes out of my piston skirts.

R.J. thanks for helping me work that out. Its what I was afraid of. Looks like I'll be getting some different springs...maybe not the pricy Cranes but, definately something.