Someone above mentioned the "VR Buick". Hmmm...the VN to VT used the 3.8litre OHV V6. No timing belt or timing chain. They did have a serpentine drive belt for the power steering and AC pump but that's about it.
The general rule of thumb is that timing chains should last the life of the engine. Rubber timing belts have to be changed between 60 to 120,000 kay, depending up the manufacturer's recommendation. It's not an easy job and you often have to change the belt, water pump and, often, the tensioners. I owned a TJ Magna and that ate timing belts every 100,000 kay. It was an expensive job to change and if you had a d'head mechanic who didn't tension the belt properly you were in for a pile of trouble.
As to the VE timing chain issue...well, I can't talk about the chain quality. I do know someone who replaced the GM chain with a "better quality" aftermarket chain and they are now very happy. I own a VF and, apparently, the "chain stretch" issue was solved by then. I have a great mechanic, ex GM, and he has told me that the secret to keeping the chain healthy in a VE or VF is to make sure you are scrupulous about your oil changes and that you always use the recommended oil viscosity and a top brand synthetic oil.