Thread: Need information on fitment of 95-96 4.3 Chevy engine

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Hi Itoldyouso,

Looks as though we are in the same boat, or at least in the same lake. Sometimes it feels like a whirlpool. I questioned him about how the mechanic knew the heads needed a valve job just by looking at the plugs. He must be a lot better than I am. I have worked at 4 different GM dealerships before I became a Journeyman Machinist.
My Nephew is a good kid and I want to help him save some money. He is self employed in home construction and needs his truck. Like I said, I would prefer to replace the engine with a 305 or 350 of similar vintage. Most of the wiring will hook up with a few changes and the exhaust. Being self employed money counts so I can see why he needs to try and do it his self.
Not necessarily in this case, but most of the time when I try to help someone out I wind up doing all the work, they are gone and I am still wondering how I will get my own stuff done. Seems it is vastly one-sided.
The 4.3 is a good engine but it stands to reason when it has to work so hard and require more throttle to keep up that sometimes the larger engine is a better choice.

Hurst... STOP !!!! It might not need a Valve job... I was a GM line tech in the 80's-90's and 00's. The 94 engine used a Linear EGR valve that gave us a fit. Sometimes the valve itself would be bad, OR a hunk of carbon would get hung up in it and stick it open. Now, it gives the syptoms of a fried valve. So, pull off the EGR, check it for chunks of carbon stuck in the printle valve. If nothing there, then get the valve checked. Also, if there is a hunk of carbon in it, pick it out, then cap the hole going to the intake side and start it up with the valve off, this will blow any other loose carbon out. then reinstall valve. It would also explain the sooted up spark plugs. It can cause, low power, bad or no idling, excessive black tailpipe smoke, and a miss. The problem was so bad, a service bulletin was issued to address it;

( I stole this off another site )
Repeat failure
Repeat failure is a common problem. You can recommend a top engine clean to the customer and attempt to clean loose carbon from the upper intake. GM has noted the problem and come up with a software update for the PCM. Essentially, what the update does is periodically command the EGR to 100 percent opening to prevent or flush out carbon chunks. The new prom numbers were in a "special policy" procedure bulletin and not a regular TSB. The special policy number is 96067(A). It refers to '92-'94 S/T, M/L and C trucks with the 4.3 V6 engine and linear EGR valve. The bulletin number is 67-65-38. It refers to '95 C, S/T and M/L trucks with the 4.3 V6 engine and linear EGR valve.

Weasel Diesel,

Thanks for the information. I have not seen the truck for almost a year. I was planning to have a look at it later this week. I would not have just yanked it apart without checking it though. No way I would take someone's word for something like that, too much work. If I pull it apart it is because it needed it.
I was unaware of the bulletin that GM had put out on the 4.3. It has been several years since I worked for GM. It was far enough back that we were not called Techs. I certainly appreciate you taking the time and trouble to post this information, it will give me a heads up and I will check it first thing.
I have always found this to be a pretty decent site to find information.