Need bolts for 3400 Top end

[TazMan]

I've got a 3400 Top end for my 92 Gen 2 GP, but I don't have any of the bolts. Can I get the intake manifold bolts in a set or do I need to find the size of each bolt and get them individually? Do they need to be new or can I search for a used set somewhere? Thanx for reading

[IsaacHayes]

The bolts can be re-used for both the upper and lower. When putting the lower bolts in though, clean them and degrease them, then use medium (blue) thread locker on them with the correct torq. A metal felpro LIM gasket is a good idea if you haven't thought of that yet. I don't have measurements for them, but if you did you could grab some at a hardware store I would imagine. They don't get torqed down much at all.

[PCGUY112887]

Yes, the spec sheet reads something like 81 ft in of torque (made up # do not use it). Note that is not ft LBS, it's ft IN! I was trying to get it to 81ft LBS, wondering why in the hell it had to be so tight. I noticed after getting 1 bolt to about 35ft lbs, and took it out and redid it.

Isaac I don't believe any thread lock is needed? I don't remember putting any on the LIM bolts of my 3500 because I don't remember seeing any when I took it off... I may have forgotten though.

EDIT - GM book says to use thread lock for the 3100... now I am really wondering if I forgot it or if it didn't have any...

[TazMan]

Sound good. I ordered the gasket set today on e-bay. I got the Fel-Pro problem solving gasket. Just wondering, how important is using the thread locker? Reason I'm asking is cause I just changed a LIM gasket on my other vehicle and I didn't use it.

[ForcedFirebird]

I just made a trip to the JY, and came back with a gallon of the misc bolts I needed to complete my swap, along with valve covers etc. I got the covers, t-stat housing, pushrods with guides, head bolts, PCV with tubing, upper manifold bolts for $50, and I just realized I forgot LIM bolts as I was reading your thread :P

[IsaacHayes]

There is a TSB out that when you replace the LIM you buy new bolts. But all the bolts are new from GM is pre-coated with threadlocker. So if you clean up your old and thread lock them, you should be set. The theory is since they aren't on that tight and expansion and contraction might loosen them up and then the gasket will leak even quicker. I didn't put any on the first one I did, and it seemed fine for a couple years before it started leaking. I did it last time just to be safe.

The stock gasket lasted longer before it leaked than the 1st one I put on, but it was more severely degraded and leaking inside the motor. The 2nd one was leaking outside and was brittle and starting to warp. Not sure if the 2nd one was leaking outside the motor due to bolts backing out or what. It did last about 3 years or so. I guess you could always re-torq them to see if they loosened up any after a while.

[PCGUY112887]

If it's fine now, then I would just leave it and remember to go back and see if the outside ones are out of spec since you can get to them without taking the intake off.

If they are getting lose, then take the intake off and redo the bolts. I guess that is what I will do.

[SE'sarecool2]

Yes, the spec sheet reads something like 81 ft in of torque (made up # do not use it). Note that is not ft LBS, it's ft IN! I was trying to get it to 81ft LBS, wondering why in the hell it had to be so tight. I noticed after getting 1 bolt to about 35ft lbs, and took it out and redid it.

You're almost right....its Inch lbs not ft in... so 10 ft-lbs=120 in-lbs
...just so nobody gets confused.