I need help finding out what engine is in my truck. i have an 86 chevy blazer k5 with the 350 5.7 liter so it says . but the guy i bought it from said it was replaced with a crate motor. my vacuum hoses are all screwed up had cat replaced now runs like donkey doo. dies while trying to drive hard to start etc. was running fine till cat was replaced the mechanic said some hoses were not hooked up. the sticker says yma?? but i dont know where to find number on engine.

Was the time changed and is the o2 hooked up

If its a crate engine it's most likley the same 350 5.7 engine and everything should be the same if the problem happend after the cat was replaced i would take it to another shop to make sure the job was done corectly also make sure thet if there was an o2 sensor in the cat or next to the cat that it is still plugged in or there at all

On the chevy small block v8 the numbers will be on the left side of the engine look for a small step right at the head / block mating area. The numbers will be in the form of a ser# get that number and call a good chevy dealer and they can tell what engine you got. But any small block chevy crate engine will be a 350 or a 305. they will act the same as far as tune up and any vacuum hoses to the carb or trans. They interchange of a sort.