parts from Gen III heads fit on gen II heads?

[dbtk2]

Will the valveprings, retainers, locks, valve guides, valve seals, and all that from 3100 heads fit on Gen II heads? I have a set of 3100 heads that were fully rebuilt with new everything (except for valves), but i'm not planning on using them anymore (was gonna do a topend swap), but my Gen II heads need some of this stuff, so I was wondering if I could just put the stuff in the other heads?

Also, are the Gen III valves any better flow wise than the Gen II valves. I'm pretty sure they are the same size (I have a set of '95 3100 heads), but I don't know if they flow any better or not or if they even fit. The valves on my Gen III heads have had a valve job (was done before I bought the heads) but I don't know how good of a valve job or whatnot.

Thanks,

Shawn

[SappySE107]

Im pretty sure it all swaps over, even the valves. The part numbers are the same for the valves so there is nothing to be gained other than the valve work they did to them. I dont know if the valve spring ratings are gonna be good though but they should fit the heads.

[RacerX11]

The 3100 and Gen2 valves and retainers are slightly different. The retainer lock groove is about 0.020" different. As long as you keep the 3100 retainers with the 3100 valves, everything should line up and your spring installed height should be OK.

Marty

[geoffinbc]

The 3X00 springs are a better design. The progressive spring rate is more desirable for performance.

[SappySE107]

Are you sure the lock groove is different, because they are listed as the same valves on gmpartsdirect.com.

[RacerX11]

Yep, 100%. When I lost one of my 3100 valves, I went to use one of the numerous gen2 valves I had laying around, and they were different. The ridge on the locks are at a different height to compensate.

Here are the Sealed Power Part Numbers for the valves (couldn't find the gen2 intake valve #):
Gen2: V2431 (exhaust), V2432 (intake) Edit: found the number
Gen3: V4497 (exhaust), V4571 (Intake)

I checked GMPartsDirect, and these were the numbers I came up with:

1991 Pontiac 6000 3.1
10070124 (exhaust), 14091805 (intake)

1996 Chevy Lumna 3100
10166342 (exhaust), 10166341 (intake)

Marty

[v6h.o.]

marty is right on the valves. they are different from gen2 to 3.

[dbtk2]

Thanks! Sounds like I can get to this project pretty quick.

The 3X00 springs are a better design. The progressive spring rate is more desirable for performance.

What is a progressive spring rate, and what makes it "more desirable for performance?" I don't know much about valve springs except that stronger ones close the valves quicker (and harder)at higher rpm and are a litle harder to open because they are stronger, so they don't compress as easily....so please explain the difference. I'm probably going to use everything off the 3100 heads, but just so I am more informed, whats the difference.

Also, does anyone have a parts list for what is needed for removal and replacement of the heads. The gaskets and such. I think I wanna just go with all GM gaskets, but what all gaskets do I need, and what nuts/bolts do I need? I know I'll have to make a trip or two to the store to get stuff while I'm working on it, but I would like to make those trips as minimal as possible, because that just wastes a bunch of time. So, if someone has a parts list of that stuff it would be awesome if you could post it here.

Also, is there a better pushrod that i can buy. I have heard a few stories of the stock ones breaking...is this a common problem, or should I not worry about it? I was thinking about getting stronger, or at least new ones, but I'm not sure what difference its gonna make.

I also am debating between going to 1.6 rockers (which I know will not make much difference, but will be better than stock) or installing a bigger cam. With the rocker arms they will be easy to install because I'm gonna have to put the stock ones back on anyways so I can just put the other ones on instead, they won't cause any computer problems, and they should give me a couple horsepower. A camshaft is a little more difficult, it requires significantly more work to install, if I go with one too much different from the stock one (which if I didn't go much different there wouldn't be much point of changing it) then it will need a lot of computer work, which I can get done, but will cost a bit, and again, it won't be easy. And I also am not sure at what cam I should go with if I do get a cam.

What do you think?

I figure if the heads are coming off, the engine isn't going back together stock, and the heads HAVE to come off (due to horrible valve guides and a slightly blown rear head gasket, which the car has had both since I bought it 8 months ago ) and I can't hold it off any longer, so I gotta get it done soon. Any suggestions on what I should do for a camshaft or if I should even change cams would be great.

Thanks,

Shawn

[SappySE107]

I wonder why they listed them as the same about a year ago on GMPD. I had looked them all up for the site (and lost it all when the site crashed). Oh well, now I know

[bszopi]

For the gaskets, get a Fel-Pro head gasket set and then a set of head bolts, and that should cover everything you'll need. The head gasket set includes everything from the heads up (inj o-rings, TB gaskets, valve cover gaskets, thermostat gasket, etc...)

[dbtk2]

I was thinking about just going with a fel-pro gasket set, however, I have heard NUMEROUS people who have had numerous fel-pro gasket failures on the 3.1 Turbo engines. I heard of one person who had 3 of them fail right in a row, then he put in a GM gasket and had no problems, and the heads weren't warped at all or anything. I was thinking if I go with a GM gasket, then at least I know I have stock quality...I don't know that the fel-pro is even as good as the factory gasket.

This is the parts list that I can think of, if there is anything I am missing or don't need let me know:

Head Bolts
Head Gaskets
Exhaust Manifold Gaskets
Lower Intake Gasket
Upper Intake Gasket
Throttle Body Gasket
Valve Cover Gaskets
EGR Gasket

Other than that I can't think of what I need. I don't need a thermostat gasket because I have changed that numerous times and I just use gasket maker. I also am planning on getting new fuel injectors so I shouldn't need the o-rings. Anything I'm missing or don't need?

Thanks,

Shawn

[geoffinbc]

The progressive rate is achived by creating the beehive you see on the top of the spring. It allows the valve to seat and un seat easier and drasticaly cuts down on spring harmonics. If you notice on performance valvesprings (straight springs) from comp or crane they include a damper inside the spring. The damper cuts harmonics in the spring. Well the beehive shape on the GM springs does the same thing. Good for performance and good for valvetrain life