Hi Lee, I added factory ac to my 69 Firebird from a 69 2bbl 350 2spd. donor car. I can't say much about GM part numbers but the original upper dip tube is 12" long following the curve of the tube. It mounts to one of the valve cover bolts and faces the front (not the side) of the engine. Don't forget that the dip stick itself has to be longer too. Did your tube come with the matching stick? I can measure the stick too if you like. You can see the handle in this photo....http://www.mprime.com/ProjectFirebird/IMAGES/FB-ENGINE-08.jpg I can send another photo if you like. Right now the compressor is off the car so it will show the tube more clearly. ......Carl http://www.mprime.com/firebird.htm
