90 1/2T has started to need to get up to 25-30 mph before shifting and then shifts hard. All other gears seem to have to have more speed to get them to shift. Anybody else have had this problem?

Maybe your TV cable needs to be adjusted. It may be too tight.

Thanks for the reply.
Is there a procedure to adjust or check the TV cable?

There's a release button that's on the end of the cable housing right behind the bracket on the intake manifold. You press that button, and pull the cable housing back toward the firewall. Then you get in the truck and press the accelerator to the floor. The cable housing is supposed to ratchet to the correct tension. I'm doubtful that this will work for you though because it sounds like your cable is already too tight. You may just have to play with the cable tension until the shifting feels right. Some rough guidelines I've heard is that it should shift into OD when you're at around 40-45 MPH. Also if you accelerate from a stop at a normal rate until it shifts into 2nd, and then you stomp on the accelerator, it should immediately shift back into 1st. By the way, what kind of transmission do you have? I'm assuming it's a 700R4. Does it have overdrive?

Not sure of the kind of transmission, but it does have overdrive. I will try this later. Thanks

90, hmm does that also have vacuum modulator? I would think vacuum leak if it does...

Didn't see a vacuum line anywhere, just an opened ended vent hose.

If it is a 700R4, there are no vacuum lines.

You can tell what transmission you have by the shape of the pan. Here is a picture:

(Picture courtesy of Nasty Z28.com http://www.nastyz28.com)