I'm swapping out the 305 in my 1988 K1500 pickup for a rebuilt 350. I have the TBI unit off the donor truck, so all I need is a new PROM for the ECM.

Does anyone know the part number for a PROM for a 1988 K1500 with a 350 and auto trans?

 

I assume you are looking for a chip (PROM) already programmed. The un-programmed blank chip for a 1988 Silverado K1500 is # 16060836 runs about $40.00, but you would need a chip burner and software. You can get 350 TBI automatic performance chip for about $70.00 and up (search on K1500 performance chip) here is an example site http://www.performancechipsdirect.com/ . There are also more familiar sites like Summit , etc that will charge more. Hypertech makes stage 1 and 2 chips for the K1500 at higher costs. You can contact a mail order tuner and get a customized chip for around $200. Or you can go to a junkyard, real or internet and try to find one for a 350 auto there. Seriously doubt the Chevy dealer parts can help for that year, if so cost may scare you away.