3500 questions

[ForcedFirebird]

My 96 3100 valve covers are plastic... on both my sedan and coupe.


My 3500 ones were metal though.

Yeah, I knew this, but I haven't been able to pick up the 3500 gaskets yet due to funds funneling into the block and top end parts. I stll have a lot of work to do to get this going. Custom accy mounts, headers, etc. I'm thinking of leaving the 3.1 shortblock in the car for a little longer to mock up these parts while re-building the 3.4 (that should be here next Fri.). My wife is having surgery Tue, so not much is going to get done next week.

[PCGUY112887]

My 96 3100 valve covers are plastic... on both my sedan and coupe.


My 3500 ones were metal though.

[IsaacHayes]

Yes the gaskets are just to hold the pushrods while you are reassembling. Nothing more.

[ForcedFirebird]

Yeah I was wondering if you'd have issues with the rocker studs, but wasn't sure of what exactly you were going to be using. Can the guides be clearanced?

The rocker studs aren't the issue, I can either re-tap the stud holes for 10mm, or add a bushing. The tapping would probably be best, so I don't have the rockers riding on such small studs (OK if they are tightened against the pedestals).

The center of the guide hits the top of the ports. I have a set of 3500 rockers, so if all else fails, I can use them. I'll try and get some pics up later to show you what I'm dealing with. The solution I'm thinking of is cutting the center of the guides out, and running a weld bead and machining them so the rocker slots in the heads will hold them square. Or I'll just copy them on the mill and make a new piece all together. I saw that the latter 3x00's had a small guide in the LIM gasket, but I don't think it would be sufficient to hold the p-rods square to the rockers in an adjustable rocker situation.

All this will give me .499 lift at the valve with a $59 260 re-ground cam .

[IsaacHayes]

haha. Yeah some things are hard to get to. If you've done it before you can get away with taking less off. Yeah I was wondering if you'd have issues with the rocker studs, but wasn't sure of what exactly you were going to be using. Can the guides be clearanced?

[ForcedFirebird]

Got some valve covers from a 95, and pushrods/guides from a 94. I don't know what I was thinking, but the 3500 heads have 8mm holes for the rocker studs, and the earlier heads have 10mm. They will take a little modification, but think they will work. The ports are so much bigger on the 3500, that they interfere with the guides. Going to get the valve covers cleaned up and painted, then post pics.

I feel bad for those of you who work on the FWD 660. I had to take off a lot of stuff to get to the thermostat housing I needed.

[IsaacHayes]

If the 94/95 is plastic skip it and get an aluminum cover. Any 3100/3400/etc works. Other than that looks like you are on the right path. Do post pics of those rockers when you get em going!

[ForcedFirebird]

If using gen3 heads and intake (3400/3100/3500) then you'll want to use the 3x00 valve covers (they are all the same). Gen2 Al FWD head valve covers might bolt up but I think they do not clear the rockers or something. Just get some 3x00 ones and be done with it.

Yes earlier 3100's had plastic valve covers but usually they got replaced as a recall. I know my 94 has aluminum ones.

Thanks, I just need to know my optins when I get into the yard. I guess I'll be looking for a '94/'95 to get the covers, push rods, guide plates and some misc. bolts to get this going .

[IsaacHayes]

If using gen3 heads and intake (3400/3100/3500) then you'll want to use the 3x00 valve covers (they are all the same). Gen2 Al FWD head valve covers might bolt up but I think they do not clear the rockers or something. Just get some 3x00 ones and be done with it.

Yes earlier 3100's had plastic valve covers but usually they got replaced as a recall. I know my 94 has aluminum ones.

[ForcedFirebird]

i see what you ment..


yah, the gen2's will bolt on but you'll have to make yourself an oil fill neck, also there was rumors that you needed to clearance them a little for the rockers...

Thanks again. I'm sure if the stock covers need help with the stock rockers, they will need halp with the 1.7's I'm planning on using. Got to the JY too late today had to tune up the F150. I'm going to try and grab a couple of sets. I have a key to a CNC shop, and am thinking of making a set, and use the stockers to start. If I have to, I'll cut the two in half and weld them together to make them taller .

[Superdave]

I have an iron head engine . So I'm guessing that means the gen2/3 interchange. Thanks again guys.

Now I've got to get to the yard.

i see what you ment..


yah, the gen2's will bolt on but you'll have to make yourself an oil fill neck, also there was rumors that you needed to clearance them a little for the rockers...

[ForcedFirebird]

you don't want the older gen3 valve covers.. they are plastic.

yours should work just fine.

I have an iron head engine . So I'm guessing that means the gen2/3 interchange. Thanks again guys.

Now I've got to get to the yard.

[Superdave]

you don't want the older gen3 valve covers.. they are plastic.

yours should work just fine.

[ForcedFirebird]

I would just get some Gen3 guide plates from a 3100 that has non-roller rockers. 94-95. Also I think you might need different pushrods that are hardened, unless they are all hardened? If the 3100 rods are the same length as the 3500 (I would assume so) you could use the ones from the same 94-95 non-roller rocker 3100.

Thanks. Thats the info that I was looking for.

Do the valve cover also interchange? If so, I could probably get the rest of the parts to make this work. It's too bad, though that the earlier heads have 10mm threads on the bottom of the rocker studs (3500 has 8mm), otherwise this would be a real cheap rocker swap.

[IsaacHayes]

I would just get some Gen3 guide plates from a 3100 that has non-roller rockers. 94-95. Also I think you might need different pushrods that are hardened, unless they are all hardened? If the 3100 rods are the same length as the 3500 (I would assume so) you could use the ones from the same 94-95 non-roller rocker 3100.