Timing

anyone change the timing on a 91 lumina or know where the belt is located.

I'll assume you have the 3.4 DOHC engine.
Head on over to 60degreeV6.com, they have TONS of resources for you there as far as cam timing and instructions go. The belt is behind the timing cover, accessory end of the engine. Pop it off and have at it.

It'd also be a good idea to change the belt if you haven't in a while.

My original belt went about 70,000 miles. I had the local Chevy dealer replace it as a precaution. The new belt went less than 20,000 miles and was ripped to shreds on the inside edge. Looked MUCH worse than the first belt--somehow they missed that the pulleys were toast the first time. I wound up paying for the whole deal the second time, too. No mercy at the dealership.

ne 1 ever put a timing chain in a chevylumina 3.1

Yes; its not too difficult. Just a matter of taking the old off, clean the sealing surfaces, put the new on, close it up. You can grab a $15 Haynes manual and it'll basically step-by-step you through it.