They are pretty swift, yea. The later you go in the C4 generation they better get, although I prefer the earlier TPI cars because of their sharper styling, digital dashes and more interesting engine.
The LT1's a stout motor, the only real issue tends to be the Optispark distributor so make sure it's been replaced or budget about £150-odd for a new one. Again, I prefer the earlier L98 because it's easier to tune and get bits for (the LT1 has its own block/heads etc and a reverse-flow cooling system, only interchangeable bit is the crank IIRC). It's still a good engine though.
Autoboxes are good, six-speed manual transmissions are hefty but tough. Buy on condition not mileage, although a clean low-mileage car is ideal.
300bhp and 330lb ft standard from the LT1. Weigh just over 1500kg. 0-60mph in about 5.7sec, 14sec @ 100mph 1/4, top speed of about 160mph, 0.89g in the slalom standard. Those are for the six-speed manual.
Easily improved upon as well. Lots of kit as standard, climate, cruise, electric seats/windows/mirrors, heated rear hatch glass, ASR traction control (great), limited-slip diff, etc. Generally very reliable too, it's only really the VATS key security system that can be a pain as well (all provided you buy a good one, mind).
I used to do about 28-odd mpg on a long run in my auto LT1.
Just look for crash damage, worn weather seals, signs of neglect, listen for odd knocks or rattles. Should feel tight, lively and eager. Engine should run smooth and idle quietly too (within reason, if it's got an aftermarket exhaust). Keep an eye out for botched wiring and dubious aftermarket kit too.
Really good cars the later ones, do miss my '95 but at the time I still preferred the earlier models.
People who rave on about bhp/litre need to get out more, unless we're talking about something truly exceptional. Most of the time you're missing the point, and there's a reason why the figure's low.
C4's a really good car in general too. Great cruisers and very practical to boot. Go some and good fun to drive when in fine fettle too, although the auto versions obviously lean more towards being outright GTs rather than the more sporting manual models (especially if they've got factory uprated brakes etc).
You looking at the blue one on eBay? Looks pretty honest. See if you can get them to send you the RPO codes so you can see if it's got any nice options, like heavy-duty brakes or uprated cooling.
http://forums.corvetteforum.com/c4-general-discussion/956104-c4-rpo-faq.html
Bits are cheap too, so shouldn't break the bank to run - even if you have to import them. There's a fair few suppliers here for parts and odds and sods as well.
My old 1995 C4 (had an '86 and an '88 too):
