OK, I could have been more explicit. You're pulling the timing cover off anyway; fon_dle the chain to assess how much slack it has. If there's little or no slack, there's no reason to replace the timing set.How would I know by looking at it...?
The chain and new sprockets are <$50. I'm inclined to replace it put it out of my mind forever. There are dozen different options from Melling and Cloyes on rockauto.
Really? "Fon_dle" is censored?
Another option which doesn't require removal of the timing cover, is to put the crankshaft exactly at TDC, TURNING THE CRANKSHAFT CLOCKWISE AS VIEWED FROM THE FRONT OF THE ENGINE, and remove the distributor cap so you can look at the rotor. Then turn the crankshaft counter-clockwise until the distributor rotor starts to move. At the instant that the rotor begins to turn, look at the timing marks to see how far the crank has turned, in degrees. 0--5 degrees, timing chain slack is acceptable. More than 5 degrees, either the chain is worn, or the distributor gear/gear on back of camshaft is worn, or both. Inspect distributor gears, and if they're good, replace timing set.
If you do replace the timing set, I'd take the time to make sure the camshaft timing is where it's supposed to be. Errors in the machining of the crank or cam gears can affect cam timing, and you won't know unless you check using a degree wheel and dial indicator system designed for that purpose.
MOST of the SBC timing chain options won't fit your truck. The Vortec small-block can't use a double-row roller chain, or a wide link-belt chain as there won't be enough room to have the wider chain and the matching lower (crankshaft) gear and still fit the crank sensor reluctor under the timing cover; and the timing gear for the cam may have a bigger bolt-circle that won't fit the step-nose roller cam. You can immediately narrow your timing set selection by buying only a timing set that fits a '96-2000 (?) Vortec small-block engine WITH the crank sensor.
The "first-design" timing set for Vortec engines was a "silent" link-belt chain, which I find perfectly acceptable but they're not "in style". The "second-design" is a single-row roller chain, which again is perfectly acceptable.
I bought a Vortec short-block of unknown mileage, when I rebuilt it, the single-row roller timing chain was so perfect I re-used it.