88TPI406GTA

..with stock components...

I am going to be redoing the valve stem seals on my L98 and would like to replace the stock high mileage valvetrain components too. Does the L98 use the same keepers and retainers and valve springs as the older SBC engines?

I have the stock roller cam and stock heads…what would be a good replacement valve spring? Just go to the auto parts store and order stock replacement valvetrain parts from Sealed Power? Any preferred brands?

TIA…

Stekman

I am not a fan of GM factory springs (or the likes of), nor will I ever be.

Comp 981

88TPI406GTA

I had looked at the 981 when I did a search...

But, Stekman, in a different thread, you seem to indicate that the 981 springs are for a flat tappet cam.

https://www.thirdgen.org/techbb2/sho...+valve+springs

Just to clarify..I have the stock hydra roller cam...

Yes, I know that a spring is a spring, but I thought that hydra roller springs had to handle the faster ramp up of the hydra roller spring..where a flat tappet spring did not.

Stekman

Yes, yes. Thta is USUALLY the case from me, isn't it

Well there are exceptions. Aftermarket versus factory (not some small cam, that FITS stock specs, but a true stock cam). Although, keep in mind, they ARE better than stock still.

now, 2 reasons, and a thought, for the 981 suggestion:

1.) There is absolutly nothing radical about a stock cam that screams larger spring pressures. Most people, if they CHOOSE to go with a stock setup, AREN'T thinking about high RPM operation, which usually keys the larger spring selection from me.

2.) Partially stated in #1, but, judging from the sounds of it, you are shooting for something to get you by; nothing radical or fancy, just a reliable DD that doesn't really see high RPM operation. That being the case, you will probably won't be machining the heads (which the 986's and the 987's both require).

Here's the thought: what ARE the intensions for the engine.

Food for thought, if you really do want higher spring pressures, like such on par with the 986 or 987's but DON'T want to machine the heads, Isky sells the 235-D springs with 130 lbs of seat pressure @ 1.750" installed. They are good to like .550"ish lift. I have a set I will be using on Vortec heads. I'm sure there are others, I know Lunati makes a factory seat size spring with 130ish seat and good for mid 500's in lift.

Oh and about the ramp rates, yes that is usually the case, but, like i said, there is nothing radical about a factory SBC ramp rate, flat tappet OR roller.

Side note, holy smokes, I can't believe you dug through all that to find the 981 for a flat tappet There must be another post from me where i say something along those lines...oh well.

*EDIT* I see where you drew that conseption about 981s for flats only. What I meant there was I will be using them with a flat tappet cam. (ported 416 heads). My isky's, which will go with a hydraulic roller cam, are on the Vortec heads.

88TPI406GTA

Stekman...your assumptions for #1 & #2 are correct. It sounds like I will just go with the 981 springs...with a stock cam, heads and valvetrain, along with a slightly modded TPI setup, my functional redline will be about 5,000-5200 rpm anyway...even if the valvetrain could do more, the TPI setup won't

Thanks,

88TPI406GTA

I found a local Checker that had the Comp 981 springs...but I have another question.

For my application, is it bad to go with stock type stamped steel locks? Or is it really important to go with machined steel type locks?

Thanks,

Stekman

Since you are doing nothing really major, I don't think it would matter too much on lock choice. Me, I would still get the aftermarket steel locks. I don't like things that are stamped and steel (think, factory rocker arms). And for retainers, get the good kind (not factory replacement i.e. rotators and such).

88TPI406GTA

What is the difference between 7 and 10 degree locks? I assume that one would have to get the retainers to match, right? Stock locks are 7 degree stamped steel, right?

Why not use the stock retainers, just because of stamped steel?

Also, what do the rotators actually do?

My questions may sound very basic, but of the 2 350s, 1 305 and 3 different incarnations of my 406, I have used aftermarket valvetrain hardware in all. Never used the stock stuff.

Stekman

The 7 or 10 degree refers to the angle of the seating between the lock and the retainer. Correct, you need matching retainers. Correct again, factorys are stamped. I've reused factory locks before, though, in a pinch.

Stock retainers are bad. They are desined to work in conjunction with other strange designs such as the rotators.

Exhaust rotators are pretty much pointless dead weight on the top of the valve spring. To answer your question though, their purpose was to rotate the valve as opened and closed. This, I guess, was supposed to make the valve take the exhaust heat evenly. But in the end, just added dead weight.

Basically, get an aftermarket setup that is designed to be pretty much straight forward: 1 piece to do 1 function with no half-assed devices inbetween.