Early Vortec 4.3L identification

Hi,

I'm working on a 94 Chevy 1/2 ton p/u with a Vortec V6 4.3L engine that has the plastic valve covers with "Vortec" written on it. I want to replace the engine with one from a junkyard. My question is how can I identify an original (not converted) early Vortec engine once out of it's original body?

Did some of the early Vortec engines come with regular steel valve covers that didn't have "Vortec" stamped on it? The junkyard is trying to sell me an engine that does not have the Vortec on the valve cover and instead of having a engine ID (located at the back of the block) of 4.3L S6, it has 4.3L S3 - what's the diff?

thanks for your help.

If memory serves I beleive all valve covers say Vortec on them if it had the Vortec Engine.. he may be selling you a 4.3 that had a TBI system only. The Valve overs should fit either way, but I understand what you are trying to do.

I realize that the valve covers are different but what is the difference in the motors? And how do you id an original early model Vortec versus a plain 4.3L V6 - are there some numbers on the block or something?

I guess what I'm trying to say is that anyone could switch the valve covers and intake between a non-vortec 4.3L V6 and a Vortec 4.3L V6. Soooo, how do I know if it's an original Vortec motor or a switched?

I guess what I'm trying to say is that anyone could switch the valve covers and intake between a non-vortec 4.3L V6 and a Vortec 4.3L V6. Soooo, how do I know if it's an original Vortec motor or a switched?

From 94 model up they all should be vortec engines. The thing to look out for is some were throttle body fuel injection , some were center port injection.:smokin:

Isn't there a VIN number on the block and can't that be decoded to tell you what engine you have? Anyway, this might help a little:

http://www.s10blazers.com/sserieshistory.htm