[PontiacMatt72]

Looking for recommendations on valve springs.

Lobes 4253B (intake) and 4214B (exhaust)
Both .440 lobe lift (cam card actually says .441)
Card is attached

Running this in a 535 with first gen E-heads ported to approx 335 intake cfm at .700 lift. Race engine. Rpm range will be wherever it stops making power I reckon. I assume 7000-7500 range?

[mysticmissle]

need valve installed height with retainers and the keepers you are going to use to narrow down the choices, and rocker ratio

[PontiacMatt72]

Open to suggestions on that (installed height, etc) as well... probably going to get all new valves.

Using Harland sharp 1.65 rockers with stud girdle

[Formulajones]

Very similar to the cam Tony Bischoff used for my fathers 571, also with 1st gen round port E-heads.

Tony used 943-16 springs installed at 1.915" with 240 lbs. seat pressure. He uses Harland Sharp 1.65's as well.

Here's the cam card.

[PAUL K]

We usually use atleast 240 seat and 700 open with those lobes. I hope you're using the HD Harland Sharp rockers.

[grandville455]

PAC 1289, That's what I'm using, they were 255@2.00 /640@.745 new tested

[Steve C.]

https://www.racingsprings.com/1200-S...-1243/Item/239

PAC 1243

Same as Comp 943 spring.

240 at 1.900"

Both Dave Crower with a custom sold roller with .4250" lobe lift (260 @.050) and John at Bullet Racing Cams recommended the PAC 1243 spring for my Ultradyne MSD solid roller with .4300" lobe lift and 255 @.050.

Both with 1.65 rocker ratio.

.

[Bill Eveland]

My comp cam sr is 280/284 with .440 lobes . Using comp 944 springs.
190@1.950
747@1.200
HS 1.5 rockers with girdle for d ports

[PontiacMatt72]

Originally Posted by PAUL K

I hope you're using the HD Harland Sharp rockers.

I currently have a set of "originals", but if they aren't up to the task, I have no problem upgrading to a set of "HD's".

Probably deserves its own thread... (Rocker Arms). I'll do a search first.

[Probird]

I'm using Pac 1225's. They are 250 @ 2.00 installed height. If I remember right my installed height is 1.95"

[joes455]

Is there a spring graph available for the pac .need .600 lift spring load

[johnta1]

Not sure if this is what you want?

PAC spring rates

[frbformula]

I run the comp 944 springs as well. .646 and .648 lift solid roller

[Formulajones]

Originally Posted by PontiacMatt72

I currently have a set of "originals", but if they aren't up to the task, I have no problem upgrading to a set of "HD's".

Probably deserves its own thread... (Rocker Arms). I'll do a search first.

My father uses the originals on his with the cam and spring pressure I listed above on his 571. Been fine for 2 years now and quite a bit of street driving since. Tony went over them and didn't have any issues at that time. They were used for about 10 years on the previous motor with less spring on a hydraulic roller. So they were just put back in service.

My choice would be to go with a set of Crowers anyway.

[S/st 54]

Originally Posted by PontiacMatt72

Open to suggestions on that (installed height, etc) as well... probably going to get all new valves.

Using Harland sharp 1.65 rockers with stud girdle

My 2 cents.... Get you some valves that are tall enough to give you a 2.100 installed height.That way you have room to grow to a valve lift your comfortable with,then once you have run a year or two with that lift trouble free your able to add more rocker ratio or more lobe lift and rocker ratio to quote "turn it up" a bit. But you will most deff already spent the money once on a good set of valves! Also there are a ton of great 2.100 installed height springs out there to get you the spring psi you desire. ...... Room to grow....that was always my thing when I ran Pontiac stuff unfortunately some folks never understood that because they never raced in this century.