It's no wonder the Slant 6 is so great!
When I turned 16, I inherited a 73 Gold Duster with the Slant. It was an extra car at our house. Had been sitting in the garage for years due to a burned ballast resistor and I figured it out. I had to drive that car for a year. Hated it. The only good thing about the car was it had an impressive A/C to deal with the Texas summers. However, turn on the A/C and the car barely had enough power to pass itself on the highway!
Rat Rod Al was right about the oil filter and distributor... so easy to deal with! Ha-ha! OMG what were those design engineers thinking?? I suppose engines were easier to service if installed in a truck, but the A-bodies... holy crap it was a pain! Oh sure... let's mount the oil filter upside down! Customers will love that feature! Helps lubricate the driveway! I was just glad mine had electronic ignition and didn't have to deal with points! And those damn spark plug tubes... another brainstorm idea!
A year later, I bought a 72 Gold Duster with a 318 and 69,000 miles from a lady for $400. I drove that car for the next 26 years! Talk about a HUGE upgrade! It was amazing how fast that car would go compared to the Slant. I really don't think there was much difference in fuel economy between the two. But, that could have been because I always had the pedal all the way to the floor to try to make it go!
With all that smack I talked on the Slant, it was indeed reliable and took a beating from a 16 year old kid that would slam it into Low 1 and punch it while still moving backwards just to try to leave a mark on the road... and it would. Just not a very big one! LOL In hindsight, it was the perfect engine for a young boy to have. I bet that if I had anything bigger, I would have ended up in a ditch or lots of speeding tickets (even though the speed limit was 55 then). I used to know a lot of people back then that had them. I never heard of anyone destroying them. They just kept on going.
Today, I would love to find an old A-body or truck with a Slant. I would likely do a few small upgrades just for giggles. A 4 bbl and some headers would bring me a smile.
This much is certain... they cannot hold a candle to ANYTHING in the past 4 decades in stock form. BUT, it's important to keep in mind that when this engine was first introduced, it was a technological marvel. Big Mama Mopar probably never expected this engine to exist for as long as it did.