We have a '94 S-10 Blazer Tahoe with the 4.3 V6, and you should have plenty of power. If the GMC Jimmy that you are buying is a four-door, the wheelbase should be adequate for the Caravel
. Fully loaded, you will likely be at about 85% of the trailer tow rating for your Jimmy. Based on our experience with the '94, I would suggest the following before towing:
VERY carefully check the cooling system (ours went into near meltdown just over 100,000 miles). At the bare minimum, I would suggest a flush and fill of the cooling system, a new thermostat, new hoses (if the age of the ones on the truck are unknown). An auxilliary transmission fluid cooler is almost mandatory with this rig. Also, as a precaution, I would suggest having the cooling system pressure checked to be sure that their isn't an internal/hidden leak - - we had one that flooded the valley between the cylinders - - the end result was damage serious enough to require replacing the engine (oil was diluted damaging main and rod bearings as well related damage caused by the coolant thinned oil).
It would also be a good idea to have the attaching bolts on the receiver platform checked for proper torque - - I have been suspicious of all GM receivers after the issues that developed with some of the factory Suburban receivers a few years ago - - now have mine re-torqued at each oil change (both Suburban and Blazer). The typical 4" drop/raise adjustable ball mount will likely give you access to the proper hitch height for your Caravel
if the receiver height is similar on your Jimmy to what we have with the Blazer - - you will want to use weight distribution with the blazer as the hitch weight of the Minuet causes our Blazer to squat noticeably without the distribution bars - - the Minuet has a Reese Dual Cam sway control, but it has a hitch weight of 440 pounds when loaded (at least 400 pound hitch weight is required for the dual cam to be effective according to Reese).
It is very difficult to tell whether there will be a clearance issue with the tires. I checked the spare for my '78 Minuet 6.0 Metre which is a Good Year Marathon P225 75 15 (bias ply - - an original from 78) in load range C and it is rated at 1820 pounds at 50 psi maximum inflation. I suspect that load range C tires will be a bit light on capacity for your Caravel given a dry weight of 3,290 pounds. I would suggest taking the trailer to the Good Year dealer and allow him/her to spec out the tires - - especially if they have to be special ordered that way if they don't fit it will be the dealer's responsibility and not yours.
Good luck with your new to you combination. The Blazer/Jimmy makes a very maneuverable, peppy runabout for local errands - - ours averages 20 MPG in all around driving - - not enough towing experience to comment on that side of the equation yet.