I remember when I bought a used Chevrolet El Camino back in 1985 with 25,000 miles, the salesman said, you should get 150,000 miles out of this car, it was a 1983 model.
I remember at 100,000 miles, the EGR vale was clogged as well as the port in the intake manifold. My mechanic friend said, we are not going to put another 1 in, because you will have the problem again. I eliminated the EGR valve and put on an intake manifold with no egr provision and capped off the pipe that went to the exhaust manifolds, when I put headers on, the pipe plug that restricted the exhaust was totally crudded up.
The car ran better with no EGR valve, and I think that the emmisions equipment in the 1980's that GM had was junk. I also replaced many parts and the car ran better, here are some parts:
1) Non emission carburetor
2) Non emission distributor
3) Non emission intake manifold
4) Edelbrock Water Pump
5) Aluminum Radiator
6) New pushrods
7) New rocker arms
8) Better Timing Chain
I mention the timing chain because the original 1 had NYLON GEARS, obviously I put a timing chain on with metal gears.
I also replaced the PCV every year. My Dad has a 1979 Pontiac Bonneville with 200,000 miles that is still going, but the only emmisions device is the PCV.
I also replaced the valve seals at 364,000 miles.
I have done a lot of work on this engine, but what has me annoyed is that I know a few guys that had japanese cars from the early 1980's and have gone well over 300,000 miles with only routine maintenance.
I will not tell you what I did when my converter clogged, but after getting rid of all the emmisions junk, I still passed emmisions and the hydrocarbons were the same.
I believe there was an article in Hot Rod magazine back in 1977 or so that did an emmisions test with the converter and without, and the emmisions were the same.
GM is also notorious for building cars in the 1980's with restrictive exhausts, except maybe for the Corvette. I had a single exhaust with a Y-Pipe. 1 of the pipes went underneath my oil pan and then up on a 45 degree angle to meet the other pipe that went down to the single exhaust.
I eventually ran dual pipes off the manifolds, basically a true dual exhaust and the car ran with some more power and it was no longer a slug. The shorty headers woke it up some more.
There are very few people who have done what I have done on a 1980's small block chevy engine. Every part I have replaced has been better than what GM put on the car, and the stuff they put on that I took off made it better.
Too many people remember how junky these american cars were back in the day, maybe they are good today, but too many people are happy with there foreign cars.
I am sorry but the Big 3 seem to want people to buy new cars every couple of years, trade there old car in so they can resell it and make some money. That's fine if a new car only costs $4000.00, not when it costs $25,000 or more.
Imagine what will happen in a few years when the Chinese start making cars, Hyundai was once a joke, but not anymore.
I just feel that foreign cars hold up better in the long run, and I know a lot of people agree with this statement.
I heard that when the Chinese start making cars, they will be about $10,000, and from what I heard on the news a while back, these will be the high end cars.