ok, i have a 91 formula with the 350 L98. I'm trying to get my TPI apart, but the throttle body is sticking to the plenum and the plenum is sticking to the runner rails. I can't seem to break the gasket seal. I tried wiggling them back and forth but that didn't help. A few hard pulls on them didn't help either. What do I do to get these off?

Also, I read somewhere that you don't need to use gasket sealant on the gaskets themselves. Is this true? I'm guessing if I don't use sealant, then it won't be so hard to get the TPI apart next time.

 

91,
Those gaskets could well be originals, and if that is the case they shouldn't have any sealants. Obviously, they don't need any.

Try soaking some penetrating oil or even water into the gasket paper to swell and soften the gasket. Allow a little time. You may also try to wor a slender screwdriver tip into the corner of the assembly. Don't pry with the screwdriver, just push it straight in to wedge the gasket apart. Keep a couple of bolts loosely threaded into the assembly - just enough to prevent the item from dropping when you do get the gasket to release.

As for the plenum, you will likely have to loosen the upper AND lower runner bolts to get it free. Again, a little penetrating fluid or water to swell the gasket paper can help.

If you discover that there is no sealant, don't be surprised. As long as both surfaces are thoroughly cleaned of any gasket remnanants, there should be no need for sealant. However, when you reassemble the TPI, it would be a good idea to apply some anti-sieze compound the the fastener threads. This will certainly make it easier next time.

As long as the plenum is coming off, you may want to remove the EGR valve to clean the passages in the intake and inspect the valve seat. Breaking loose the distributor clamp bolt and getting a little anit-sieze on there maight be benficial too, since that area is not easily accessible when the plenum is installed.