I had a 74 Slant Six in a Dodge B-100, which my live in girlfriend returned home with and noted that it was making a lot of noise. I went out and started it, to find it knocking badly and the oil light on.Oldest is a '99 and the newest is a '07.
Had a slant six in my one and only Dodge. You changed the breather cap on the rocker box every spring. If you forgot, it would blow every bit of oil you had in the crankcase up into the carb and would foul all six plugs. It got 10 miles to the gallon off a cliff with a tailwind and would top out at 67 MPH with your foot through the floorboard.
I found the problem to be a hole a rock punched in the oil filter and replaced the filter and oil so as to hopefully be able to drive it to the shop for an engine rebuild. As soon as I fired it up, it went knock, knock, clatter, bang and then smoothed out and quietened down. I put another 100K on it before selling it and except for a slight drop in oil pressure ran fine.