[Rob Channell]

Randy's idea on the 97 for the 5.7 liter Vortec motor is good. I like it better than both the 93 5.7 liter and 2003 5.3 liter I have owned.
There is a chevy truck forum out there somewhere that has some decent searchable information to get an idea of how common these failures are.

Here are a few issues I have run across:
Fuel pump - Fuel pump has been a problem(once). It requires dropping the gas tank to replace and most mechanics around here recommend AC Delco replacement over the cheaper stuff because it is so much labor time to replace it and the failure rates for the cheaper import parts are supposed to be higher.
Transmission - The transmission specialist that rebuilt mine said the 4L60E transmissions seem to last to somewhere between 120-140k. A rebuild was ~1.1k with him doing it all. For my other vehicle I found one used out of a wreck that had $20k on it for $400. Most used ones have less pedigree and cost closer to $700. Not worth the risk IMHO.
Plastic intake manifold - There is a plastic intake piece that becomes unsealed and/or warps after so many miles or heat cycles. Fixing this was around $700 IIRC.
Brakes - cheap. I did them myself. New drums, discs, shoes, pads. Few hundred for all
A/C system - not cheap, $1.5-2k for full system
Door handles break. I have had one exterior and three interior to break. cheap. The interior are in the "help" section at Autozone. ~$15