1996 Chevy K1500 reverse issue vortec 5000 5.0 305

[K1500chevy1996]

Hello everyone.

i recently purchased a 1996 chevy k1500. it has 89,xxx on it. it has the 305. the issue im having is when i put it into reverse sometimes it dies right away, sometimes it has no power like it will bog down then just quit, and sometimes it will squeel the tires meaning that it is running correctly. it is NOT slipping. the motor runs good, i mean it only has 89 thousand miles on it. it is just aggrivating becasue i want to plow with this truck and i need 100% power in reverse. i have replaced the cap rotor wires plugs. somone told me to repace the entire distributor, and i will do that next week when the part comes in. what could be causing this? is it motor or tranny related? i am stumped. please help lol