Thank you for all the info! I appreciate it because i look for very affordable cars to repair such as the caprice, the generation before 1976 is great but huge and bulky and the 1991+ is often destroyed by 1990's police and nyc cabs around here. A bit more personal use impalas and caprice classics in the 80s i believe. The two door would be a gem, two door caprice classics from like 82-90 are awesome ( not sure what years they made the coupe) the 1989/90 cars come with fuel injection? Also of course i wouldn't cut anything for some ridiculous speakers, just a plain pioneer or bose setup would work i think, seems like an easy car to work with wires. And no no! no big wheels! ahhh! i would very much prefer spoked classic rims with white walls or gold walls , i see these cars for around 2000-3000$, i might go ahead and get one very soon.
The 1989-90 Caprice SEDANS had an TBI 305. The 1985-88 Caprices and Impalas also had the 262 V-6 with TBI. The 262 could be ordered as a credit option in 1989-90, mostly for cab fleets. I can attest that the TBI 305 is pretty good on gas; even the TBI 350 returns decent mileage.
The 1986-90 wagons used the Olds 307 (VIN Y), which was carbureted. Warning: finding people who know how to work on the TBI systems is getting tough, and the aftermarket support for them is craptacular, as I found when the TBI unit in my '91 Caprice started to go wonky. If you get one of those cars, I would recommend very strongly that if problems begin to happen, that you'd adapt a similar vintage TPI system to your engine, a product for which both GM and the aftermarket have good support systems.
The coupes were made from 1980-82, and again from 1984-87. They're quite rare, as you noted.
I'm glad to see you actually want to make some effort to preserve a car rather than turn it into a "car"toon or worse.
For speakers, the Bose speakers used as options in the 1991-up cars will probably work fairly well in anything you buy. Pioneer's speakers are also nice and they have direct-fit replacements for the front and rear speakers.
Try the radio before replacing it; if it works well, keep it in there. The Delco ETR-series radios are very well-built and can stand up to a lot of abuse, much less fragile than any of the after-market units and still sound good. If you want an improved sound, they did make a couple of them that were of a higher-degree of sound fidelity. You might need to change the plugs, though, so check that out first.
Unfortunately, I don't know of anyone that makes white/gold tires anymore, except for possibly Vogue, and they're expensive. For a good all-around tire at a reasonable price, I like Cooper Trendsetters and Uniroyal Tiger Paw AWPs, both of which are available in whitewall.
Wire discs or genunie wheels? The discs are getting hard to find in good condition and tend to be pricey when they can be found in nice shape, even though they were quite common, and the aftermarket ones generally look terrible. I actually like the standard covers or couple of styles of optional wheelcovers- I always thought the "sport" wheel covers were pretty neat-looking.
Dayton makes a nice wire wheel that will work well on a Caprice looks-wise. I believe they were also the original supplier for Cadillac, which offered genuine wire wheels as an option (at a princely sum of $1000) on the Broughams.