Jet Provost (3 and 4) trained in the 60s. The viper was very reliable - I don't remember any engine problems at my flying training school apart from icing - no de or anti-icing kit fitted. I seem to remember that the thrust was a ton plus 8 lbs ie 2248lbs. The mark 3 was undepowered but the Mark 4 went quite well and was therefore popular for aeros and the high level trips. No pressurization though - the 'bends' were common amongst the QFIs during the high level phase!
Boofhead is right - the Viper was designed for the Jindivic drone and was therefore simple.
Happy days!
mcdhu