Ahhh the old 3.4 DOHC, not to be confused with the 3400 (which came out years later and is also a 3.4 but a pushrod) but an awesome engine in its day. An interference belt driven v6 with 24 valves in the early-mid 90s! It was quick and fuel efficient but expensive to produce and hard to service (replacing the alternator required dropping the cradle).
The old Lumina Z34s (and 95-97 monte carlo Z34s with the same engine) are collectors items in some circles but the drive train is really a mechanics only kind of rig. You would not want to own one unless you don't mind wrenching yourself as no shop will want to touch it nor would they treat it correctly. Kept up with though, it is a great engine that was ahead of its time much like the old Turbo 3.8 GNX.
The DOHC has a myth that surrounded it in the tuner community. Word was that the original design made 275-300hp NA and was dialed back by GM as they did not have an adequate transmission at the time to support the engine. GM has bucked this claim many times. Even then the power it did make was enough to tear up the 4t60 and 4t60-e they were originally mated to. IIRC you could also get your hands on a manual mated to a Getrag 283 which was just amazing. Only a few were ever made, though quite a few folks swapped in a manual and wired up a clutch as the computers of the day were very easy to work with in comparison to modern setups.
It's really funny to hear DE be refereed to as a car salesman these days, I completely forgot about that!
I loved the old Lumina esp the triple black: