According to Mechani-nut's article, the 235 first came out in '50. However, the '53 235 with powerglide was the first engine with full-pressure lubrication. This motor was carried over to '54 and used in the '54 sedans with 3-speed and solid lifters. This motor is the one that came stock in my '54 Bel-Air.

Many engineering improvements were done to the 235 between '53 and '62, when it was retired in favor of the 230/250 family. Just one example of the changes is the oil pan. There were at least 3 different styles of 235 oil pans between '54-62.

Chip

Preaching the Hot Rod Gospel according to the 4-stroke apostles:

Suck, Squish, Fire and Fumes