Did a quick followup on that - a 91 Lumina with the DOHC 3.4 would have to be a Z34 in a stock config.
Like I said, I wasn't 100% sure, but was pretty sure the engine would be the standard 3.1L.
FWIW, I own a Beretta with a 3.1 and can't imagine trying to do the timing chain with the engine in the car. The Lumina is wider, but not that much wider - probably not a whole lot of fun.
Oh, and if you need a chuckle, the Beretta has developed a lope at idle... no CEL yet, and been too busy to deal with it - am I warped because I finally like the sound of it at idle - it kinda sounds like a V8 with a cam in it through a set of headphones.
Ray
Ray