Replacing old style 604 valve springs

[A ron]

After driving 3 hours one way & leaving my car at a Nesmith builder for 2 weeks waiting on springs to be replaced (which I gave up on after two weeks) I've decided to replace them myself. I've found the Springs, Keepers/locks, & retainers at Speedway Motors. Where can I find the locators and also will I need shims too? anyone have part numbers for the locators as well as valve seals?

[A ron]

I would also prefer not to have to drive to a gm dealer.

[Matt49]

When you say locator I assume you mean seat. GM part number was 19301707 although I think that may have been superseded. You are also going to need to replace the valve seals when you do this job as the seals need to be removed to install the new seats and are usually destroyed when removed. GM part number 10212810. You will need shims if your installed heights need to be corrected. This isn't a quick job and can be a day's work if done properly. Brad Hibbard at Race-1 has some good pointers found here:

http://race-1.com/p-26187-what-should-i-know-about-604-beehive-springs.html

[A ron]

according to gm performance 19301707 is also the number for the new beehive seats. Are they the same as the old ones?

[A ron]

Thanks Matt and Brad! for anyone else with the same questions: Old Style Springs Spring Kit #12495494 Keeper Kit #12495503 Retainer Kit #19171528 Valve Seal #10212810 Locators (sometimes mistakenly called shims) #10212809

[billetbirdcage]

Thanks Matt and Brad! for anyone else with the same questions: Old Style Springs Spring Kit #12495494 Keeper Kit #12495503 Retainer Kit #19171528 Valve Seal #10212810 Locators (sometimes mistakenly called shims) #10212809

Ron be sure to read Raceone's website on the roller rockers that may need to be updated if changing to beehive springs. Don't want you to drop a valve due to rockers so be sure to check that out.

[A ron]

I'm just putting in "new old" springs haha but plan to upgrade to beehives over the winter but thanks for the reminder!

[A ron]

What kinda psi do you guys use in the cylinder?

[Matt49]

You mean for a leak down test? If so, 100 PSI. Makes it easy math when figuring percentage leak down.

[A ron]

Just to keep the valves closed for changing springs. Thanks Matt.

[brad hibbard]

50 PSI is all you really need to hold the valve up

make sure it is DRY clean air

if your having trouble getting the retainer to release---more air is not the answer
tap the retainer with a 11/16 deep well socket and hammer and it will release

never have a sealed carb hat on when airing up cylinders ----you can very easily damage your floats

Brad

https://www.race-1.com

[Matt49]

I've never used air pressure to keep the valves up. Makes me nervous. I have a good clean piece of nylon rope that I stuff in the spark plug hole and change the springs with that cylinder at TDC. I just don't trust air and if it kicks the motor over and that cylinder goes to BDC and then you drop the valve, you're screwed.