I've currently got a 305 in my 1998 k1500, and with 178,000 it is getting worn. A buddy has a rebuilt 327 will that work in my truck? Will it bolt in alright?

 

Its the same block I dont know about the ECU but the block should bolt right up.

 

If the 5.3 was rebuilt and it worked/ran correctly afterwards, than you'll be ok. I would toss all the old EFI stuff from your 5.0 and use 5.3 sensors, PCM, wiring, etc. Unless you are using just the 5.3 block without the intake, fuel system and heads and using the ones from your 5.0, then you'll need a custom tune for the engine to comp for the difference in ci. Everything should bolt from the 5.0 to the 5.3 but Im not 100% on that.

 

you'll need it ALL...wiring,pcm,everything