these are the 083 heads off an 88 L98 with aprox 80k miles that are going in my 91 L98. they seem to look ok and there was no sludge inside or anything. and all the gaskets came out pretty easily. i'll be sending 'em to the machine shop hopefully tomorrow.

 

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Have them disassembled, tanked, and checked for cracks. If everything is okay so far, they can check for guide & stem wear and flatness. When that's all established/corrected, decide if you really want to improve things and have some bowl work done and replace the press-in rocker studs with screw-in. Now a good 3-angle valve job can be applied.

It's rarely a bad idea to replace the valve springs. Use something that's intended for your cam or what you might install in the foreseeable future. Top it all off with good gaskets, and you're ready to roll.

 

can i get away with installing stronger springs without machining the seats?

 

technically you cant put bigger radius springs without machine work but i think crane cams or someone makes a cone spring for more lift with no machine work. it is the same size as stock on the bottom and gets bigger as it goes up.

 

Comp Cams makes a set. 1.25" OD at the spring pocket and 1.50" OD at the retainer. Use retainers for the 1.50" OD, obviously.

 

this plus flattening the surface, valve job and new valve seals will run me about $250. they said they will reuse the rest of the valvetrain if it checks out ok. is this typical? it is kinda steep but from seeing their shop and talking to them i think they'll do quality work. said should be done by friday.

i couldn't upgrade anything yet. just wanna bolt 'em on and see if it solves the problem.

 

Should have said one more thing: Have the top of the guides machined for positive valve seals - they do a much better job than the factory style seals. This typically increases the lift the valves can handle as well. The machine shop probably has a cutter that will do that operation and the spring seats at one time.

The price sounds reasonable.

 

well they told me they're almost done with the work. said should be done by tomorrow. i bought the felpro 7733-PT2 gasket set from auto zone and they're gonna use the valve seals that it comes with. i was reading up on different head gasket install posts and i have a few q's:

1. i read it's a good idea to use teflon pipe sealer on all head bolts. i have a white tube of permatex thread sealer with teflon. i'm guessing this is the same stuff? (probably a dumb q).

2. can i reuse my head bolts? if not recommended, will the dealer stock 'em? (no time to order any. would like to get the job done over the weekend).

3. they told me they were gonna resurface 'em which AFAIK means removing some material. but i dont know how much they'll be taking out. one thing i didnt take into account is, since the heads will be cut, will everything still line up? should i be concerned about that?

4. the new heads should be raising my compression to 9.3:1 but i think only if i use thinner dealer gaskets. these felpro ones i believe are thicker. how will that affect my ratio? i'd like to stay around 9.3:1

5. should i be concerned about the block not being decked? i know i have to remove every last bit of gasket material and leave the surface as clean as possible.

this will be my first head swap so i'm trying to gain as much info as possible. thanks for the help!

 

1) Use the Permatex thread sealer and NOT the tape. The tape will give you false head torque readings.

2) Don't go to the dealer for the head bolts. You can get a good set of from Felpro from most part stores. They have the small heads and already have the thread sealer on them. Just bolt 'em on.

3) They will be taking a surface cut of about .010" just to true up the deck so there will be no fitment problems.

4) Again, any part store that stocks Felpro has the Felpro shim gaskets.

5) If you using the shim gasket, you should have the block milled. There is no composite material to take up imperfections in flatness. Try to borrow a machinist scale or a true flat to check you block's deck surface. The machine shop doing your heads should do this for you for no charge since you are a customer.

 

 

can i use the factory gasket (part # 10105117) without having to worry about milling the block? i read that it is thinner than the felpro but not too thin as some others. so now i have 2 sets of gaskets here and i'd like to go with the factory one if milling is not required.

 

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To be honest, I don't know which one is thinner but regardless, take the block to your head shop or any automotive machine shop and let them put a straight edge on it. It really should be free. That deck should be straight for any shim type gasket.

 

i posted a pic of the heads where my old pic was. everything is being reused except the springs, which turned out to be weak. the new springs look like they have a smaller spring inside them. is this how they come stock? the guy told me they were factory replacements.

i can't have the block checked cuz i wont be removing it to put the heads in. however the guy didn't mention anything about checking it for straightness. just said to make sure everything is absolutely clean.

also he said they removed about .005" (five thousands?) off the surface.

i'll probably go ahead and use the GM gaskets.

also there is something that looks like a plug on each head that is sealed with orange RTV. anyone know what that is?

 

I'd say you're looking good for a stock rebuild.

Where are these plugs, exactly? On the side by the exhaust manifolds? If so, that's for your engine temp gage on the driver's side, and if you have it, radiator fan switch on the passenger side.

 

you can see the plug with the orange RTV in the pic on the head that's standing. the holes for the temp and fan switch are not plugged.

just saw it closely, it says "580 pioneer - void if removed"

yea also didnt wanna go too crazy with upgrading. i may end up buying an 89 L98 bird for 200 bucks so i'll need some money to fix that up a bit.

 

Can you post a closer photo of this mystery plug?

The inner springs you are describing are damper springs, and are completely normal for stock replacements.

I'd suggest using the GM gasket as well, since it will maintain your compression. FelPro replacements found in regular rebuild/valve grind gasket sets are typically way too thick.

Did you have the rebuilders remove the exhaust valve rotators and shim the springs to compensate? That would be a good idea.

 

probably talking about the heat tabs rebuild shops put on. that way if you have a problem with the heads, they can tell if the engine overheated if the tab had fallen off. i use the felpro 1094 head gaskets with the copper spray-a-gasket on my motor.

 

i posted another pic. mrr23 must be right. i didnt know what it was for.

i didnt ask the guy anything about the rotators. lemme know if you can tell by this pic.

 

i used to work in a machine shop.