Chrysler Corp had quite a few various engines in that era. Financially not the best idea. A few years later they became fewer design and cubic inch variables. A singe displacement could cover multiple divisions. Had to save a lot of development and inventory issues. Still had various horsepower ratings available but all within a common family.
I've been fortunate. I have had a lot of different Chrysler engines over the years and the only problem I have ever had with any of them was a bent pushrod in my 400 at the dragstrip.
I've had flathead 6's, a slant 6, an A engine 326, several LA 318's, a 383 B engine, a 400, three 3.7 V6, a 3.8 V6, three 3.6 V6, four 4.0 straight sixes, a 5.7 hemi, 6.1 hemi, 6.4 hemi, 2.2 NA, 2.2 Turbo I, 2.2 Turbo II, 2.5 NA, a 2.5 Jeep, three 2.0 Neon engines including my current HO. I am probably forgetting something.
My experience has been very good too except for one failure. Broke a rod on my 440 doing 30mph in 3rd. Called dealer and told them that and you could feel the laugh at the other end. They towed it in and 2 days later it was done. Replaced the rod and bearing nd put back together. No internal damage at all. They believed me then.