My GTA has 330,000 km's on it right now and runs pretty damn good considering its mileage and its body is is in great shape except for paint. I've been wanting to completely restore it starting with a new paint job quoted at $4500, I'm just wondering is it smart to dump this kind of money into a car with such high mileage? I love this car to death and want it looking pristine but I'm just scared of the engine or tranny crapping out on me after I get everything done up and I don't have plans to swap the engine or transmission any time soon.

 

There is always the chance that it will happen to you, it could happen right after paint, or never. Just depends on how well it was taken Care of

 

The whole point of a "complete" restoration is that everything is like new.
Partial restoration will always leave the possibility of something failing.
If well maintained, engines and trannys in these cars will last a really long time. But the electrics do age and will require periodic replacements.
The biggest issue with these cars is rust. The unibody has many unprotected areas where rot can start and continue unseen. By the time you see it, might be too late to save.
I don't get too optimistic on any f-body until I get a look under the carpets and fenders.
I have stripped cars that didn't look to bad on the outside just to find nothing left under the carpets or massive accident damage to the front.
If the body really is in good shape, the mileage only matters as far as how much of the suspension and drive wear parts like bearings you will need to replace.