Why, do you have another car with obd 1. Not trying to be rude but can't figure what's going on here. Your getting "P" codes? You don't have an obd 1.

 

the emissions sticker under the hood specifically says equipped with OBD1. and we bought the truck new.... so the sticker is original....then i also called PCM Performance and gave them my service number for the computer 16193495 and he said its a OBD1 in a newer casing....

 

Mine says that on the emission label also but it is not correct. If you have the same setup I do with the computer on top of the coolant tank in the engine compartment and an OBDII plug by the E-brake release you should be able to read 1.5 and 2 codes.
Before I shelled out larger dollars I picked up a cheap OBDII elm327 cloned cable for about $12 from e-bay. Then down loaded some freeware from EasyObdII just to make sure all was well. Works great.
Never heard of an updated OBDI casing. I feel the person you spoke with was just unfamiliar with our oddball setup on these trucks.
If you would like to try this feel free to PM and I can send you some links for the driver you will need for your laptop.
By the way mine comes up on the software a "OBDII Compliant" http://www.skpang.co.uk/elm327_USB.htm

 

just curious, what is your original computers service number? and yes i have that same setup that you described. were you able to reflash your ecm with that driver? if so was it custom or stock only? yes can you pm with the info
thanks so much for helping