I can't think of a V8 that would be a bolt-in swap on any stovebolt truck older than a mid-year 1955, when a 265 V8 was a factory option. Trying to install a small block Chevy V8 creates exhaust clearance problems with the steering column, and a totally different transmission, driveshaft and rear axle arrangement was used on the V8 trucks.

Engine room-wise, a Rover aluminum V8 would be a better fit, but lots of adapting would need to be done to couple it to the existing transmission and drivetrain. You would be far better off trying to find a 1954-62 235 or 261 cubic inch six. Those are almost a bolt-in fit without having to make any major drive train modifications.
Jerry

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