Also try taking the gauge panel off and lean it on the dash. On the back of the speedo the tube is held with a couple of plastic clamps. Remove them both and use an air chuck to apply 100 or so pounds of air pressure back through the hose, drive and pickup. Get some help and have them put their finger over the hole in the drive leading edge and see if the air seems restricted, or if you hear it elsewhere.

I did this a long time ago when my speedo kept acting up. Couldn't see anything lodged in the hole. Got the woman to hold her hand cupped over the hole so she could catch the obstruction as I applied pressure to the speedo end of the hose. She kept saying "nothing yet..... nothing yet.....OUCH!" Whatever the hell it was came out like a rocket!

Yeah I'll give that a shot, i'm sure it's something simple that I'm missing. Thanks for all the help guys, I'll let you know what happend.