There is no reason the 331 should be considered undependable.
Just so you know, installing a Chevy engine would destroy the value of
the car should you ever want to sell it.
As far as the hydramatic goes, if you drive any automatic with
a "liftfoot upshift", they virtually last forever. Hydramatics dropped
the rev's a lot between the 2 - 3 upshift, so it is best to lift your
foot a bit when it is ready to shift.
If your current 331 is giving you a problem, it would probably be best
to rebuild it,or, if it is not burning much oil, you may need only a
valve job. Do a compression test on it to see how much variance you
have in the cylinders. Low compression caused by leaky valves can
make them hard starting.
> I have a 1952 Cadillac Fleetwood with the original 331 CI V8 and
> Hydramatic that needs to be updated for reliable daily use. Any
> suggestions on a later model Cadillac engine/tranny that will fit
> easily, or any info available for small block Chevy/TH350 swaps into
> the early fifties cars?