it is a 91 chev 4x4 so that makes it a k? but it says Silverado on the side of the truck so which is it?

 

I thin Silverado is the trip level, I have a 96 K1500 with Cheyenne on the side of the cab and it's cloth trim. Someone may correct me though.

 

Yes pre 99 Silverado was a trim level. There's also Cheyenne not sure if 88-98 did it but there was also "custom" which was the base model. Most times Silverados came with electric doors and cloth seats while the base model came with manual doors and vinyl floor mats and seats
Post 98 all were called Silverado regardless of the trim