Question re: 3500 valves

[LeftVentricle]

They're listed in the gen 2 section; do any modifications need to be made to the heads in order to install them?

[SappySE107]

Exhaust drop right in. Intake need the valve seats cut to match up to the seat angle since stock 3.1 gen 2 is 1.72" intake valve and the 3500 is 1.76".

[LeftVentricle]

Stock lifters, pushrods, rockers and springs can be used?

[ForcedFirebird]

The only dimension that changes is the diameter of the vlave, so everything else remains the same.

[1988GTU]

Sightly offtopic, but IF you use LS1 springs, don't you need Gen 1 rocker studs to allow for valve lash adjustment?

[ForcedFirebird]

Sightly offtopic, but IF you use LS1 springs, don't you need Gen 1 rocker studs to allow for valve lash adjustment?

Why? The top of the spring seat to the bottom of the retainer won't change unless you change the valve stem height, no matter what springs are in between.

Gen2 rockers are similar to the Gen1's (flat tappet cams), it wasn't until the early Gen3's that changed to the pedistal rockers, right?

[1988GTU]

Why? The top of the spring seat to the bottom of the retainer won't change unless you change the valve stem height, no matter what springs are in between.

Gen2 rockers are similar to the Gen1's (flat tappet cams), it wasn't until the early Gen3's that changed to the pedistal rockers, right?

Guess my question was for the tappet engines and early 3100 with stamped rockers.

Someone mentioned about needing to adjust for lash if LS1 style springs were used in a gen 2 config. I begged to differ, but who am I to say... They might have put more time investigating into it than I.

[ForcedFirebird]

Any time you have flat tappet cams, the valve lash adjustment doesn't change. You need .020" to .060" preload for stock lifters, just like the roller cam motors (or any hydraulic lifter for that matter). No matter what the spring is, the procedure remains the same. That is, unless you use converting studs to go from metric to american (like to use full rollers), but then it's only a small partial turn difference from recommended specs (talking a couple thousandths).

When you get into solid lifters etc, whole new ball game.

[SappySE107]

Right, the spring doesn't have anything to do with setting rocker arm height.

3500 valves are a direct drop in minus the valve seat. A normal valve job will remedy this since you need to supply the valves to have the work done.

[1988GTU]

That's how I always thought, and I still think that. Although, I'd like to know more about something if it's has a solid factual reasoning.

What I was told recently about it is that shooting for opening and closing forces for the selected cam should be looked into. If the spring force numbers you are incorrect or not ideal, you end up getting incorrect force out of the selected springs. End result would be valve float. Using adjustable studs allow for preload changes in the spring. Hookes law (jazz F=-kx ) k is the spring constant of the spring leaving x the displacement.

[SappySE107]

Adjustable studs do not allow preload changes to the valve spring. They allow preload changes on the lifter.

[LeftVentricle]

Got my merch today. Everything looks awesome. Thanks Ben.

[SappySE107]

Thank you