In 2 years of ownership:
One head light was weak. Changed for bright night hawks. $60/pair.
Thought I might as well replace rear light bulbs as well. $20. About 30 minutes.
Ran a bit rough, so I changed fuel filter, spark plugs, distributor cap & rotor, and plug wires. After this, it ran very smooth with a bit more power. $140.
I broke the PCV breather hose when replacing the spark plugs. $8. About hour 30 minutes.
Minor rear pinion seal leak. I replaced it anyway. Easy fix $20.
Since I did a tune up, might as well replace coolant (rad & block) and thermostat. $70. I use Regular glycol (green). About 1 hour.
Rattling sound underneath. I had a shop change the catalytic converter, and replaced a section of pipe that had a kink. $700.
At the same time, replaced the rear tires with new ones. Front were still good $240. About 3 hours labour, including arrival of parts.
The windshield got cracked when big trucks were passing on the gravel roads. The shop replaced with a new one $250. About 1 hour.
Had a small tear in driver side of bench. I sewed it up and put a bench seat cover on. $30. About 15 minutes.
Interior dash and back window trim was rattling at higher speeds. Removing the back window trim removed most of it, but still coming from the center part of dash.
The AM radio has terrible reception. Only 4 stations are clear. No radio fits in the same slot. If I wanted an FM radio, then I have to put it on top of the dash. I didn't bother. I don't listen to the radio much anyway.
Some one tried to break in to the driver's side door with a screwdriver. I bought a used door handle at a wrecker with working key. $10. About 40 minutes. Removing the door handle was a pain. It required using a drill bit to drill out the rivets holding the door handle in place. Reinstalled with screws. I wish GM would use Phillip's or Robertson screws instead.
All the above I consider regular maintenance. Little things that come with age. Nothing that I can say has gone wrong, except for the lousy interior.
It is a full size truck. 1994 GMC Sierra 1500 LS model, regular cab, 2 wheel drive with 8 ft box. It was a basic work truck with 5 spd manual, manual windows, locks, mirrors, no A/C, no air bags, and ABS brakes.
The truck is powerful for a V6. It has lots of power from 1st gear to 3rd gear. In 4th gear the power drops a bit, and the OD is not much. I only use over drive for flat steady highway driving at 60-70 mph. Lower than that, 4th gear is used.
It is quite comfortable smooth ride with the bench seat. Long drives are not a problem. It is even better with a load in the bed. I am 6ft 2". There is plenty of room to fit someone tall like a giraffe, to about 6ft 7".
It could do 50mph going up long 12% grades empty. The 3.9L V6 midsize 2001 Dodge Dakota I used to have could not do better than about 37 mph up the same hill.
The GMC truck had the 5 speed manual: 1st gear: up to 20 mph, 2nd: up to 30 mph, 3rd: up to 44 mph, 4th: up to 55 mph, 5th cruises nicely at 70 mph.
Fuel economy wasn't great. About 13 mpg in town and 16 mpg on the highway. About 15 mpg on mixed driving in town and highway. It burns about about the same (1-2 mpg -/+) as the 5.7l 350 V8. The 4.3L V6 is basically a 350 with 2 cylinder cut off.
Other than fuel economy, it was a great engine. Very reliable. My friend works as a courier and has a 94 Chevy Astro van with 380,000. It still runs well. Never rebuilt. Regular maintenance the key.
The 4.3 is still being produced in the in 2wd 2011 GM trucks. It has a cast iron block and head, with SOHC, timing chain, no VVT, or AFM.
The 8ft bed had lots of room to carry gravel, plywood, tools, furniture, and to carry the ATV, Skidoo.
The GMC was rated to carry 1000 pounds in the bed. It easily carried more. Never towed with it, but it can do 5000 lbs max towing. With a full load in the bed, it easily got around town in 3rd or 4th gear on highway.
With about the same load, the mid size Dodge Dakota would stay in 2nd majority of the time. A pathetic dog it was. Fuel economy for it was about 11-12 mpg in town empty.
For the 2 years that I had the GMC, I really liked it. Solid engine and drive train. It was very simple and quick to fix with the TBI, toilet bowl injection xD. I would definitely buy another GMT400 series C/K truck, but with the 350 V8 next time.
Nothing wrong with the 4.3L, just too close to the 5.7L in fuel economy.