Place your shift selector in 2nd gear, then drive around and see if the noise is the same. You will start from a dead stop in 2nd gear. It will stay in 2nd gear as long as you keeo the throttle angle under 87.5%. If you go ver 87.5% while your speed is under 29mph, but once your speed is over 29mph the trans will stay in 2nd gear even at WOT all the way up to the stock 5600rpm rev limiter.
Your 97 could either have the 2 or 3 piece 4l60e. My 1997 rcsb 2wd Vortec 350 had the 2 piece originally. I am now running a 1999 3 pice unit.
2 piece-main body/integral bellhousing, tailstock- conventional bellhousing sheetmetal inspection cover
3 piece-bolt on bellhousing, main body, tailstock Has a 360º cast bellhousing
Some late 1997 trucks have the 3 piece 4l60e.