PB Blaster is pretty easy to obtain and works well. Adding heat is good. Have faith & go slow patience is the key here. Work the nut or bolt in both directions slowly and it will come out. It may take hours / days ta get er done.
Depending on the location it may make sense to cut em off an go. Thats something you will have to decide.

[QUOTE=Ron 78] ... Hey Norsky what do you mean "OLD GUYS" [/QUOTE]

I'll have to defer to Ken on that one...!!!

CRC Ultra Screwloose super penetrant is what I use up here in the Northland..It's made in PA.   www.crcindustries.com

Jim, give it a try..Terry

spielman538969.3773726852

[QUOTE=Norsky]

Ken Styer (kstyer) pointed me at his favorite solvent.  It's a GM product that the "old guys" call "Heat Riser Lubricant".  It works great!  [/QUOTE]

Is it sometimes called "heat valve lubricant"? #1052627

2 cruzn38969.8690740741

Throw that man a fish...!!!     

The "official" name on the can I have is Rust Penetrant and Inhibitor (Heat Valve Lubricant). Ray has the part# right.  Any GM dealership should have it or be able to get it.

Except for my local Chevy dealer...from whom I've tried--twice--to obtain
this GM product.

Know what the parts department manager told me? "We won't order it
because we'd have to order a case of it--and the other eleven containers
would just sit on a shelf and nobody would buy it."

How's that for excellent customer service?