I used to rebuild engines all the time when I was a young man. A Chevy engine would be pumping oil up to the air filter by 30,000 miles. The timing chain would fail around 70,000 miles. When rebuilding a 350 engine you threw away the cam, lifters, and valves, turned the crank, bored and honed the block with the main caps torqued and a torque plate installed because the block had no integrity. The Quadra-Jet could have been a great carb, but as usual they snatched defeat from the jaws of victory by leaking secondary fuel wells. You were always having to drill out studs and other fasteners because Chevrolet used the cheapest junk hardware they could find. I could always tell a Chevy by sound, the valves that could not quite seal and an exhaust leak. I personally would not have one. As a matter of fact, once I got out of the business, all the Chevy stuff I had was gone. I had so many 350, 4 bolt main blocks and forged crankshafts I was giving them away, except the two I would put in the back of my Dodge pickup to get traction in the winter. I won't get into the unmitigated disasters like Vegas, Chevettes, or Fieros. I won't go into engineering or racing shenanigans. But I am glad to hear they are making better engines and that yours is doing well. I hope you never have any problems with your GMC pickup.