Chevrolet Repair: u-joint replacement cost, thanks wade, camping gear

Question
I own an '83 Chevy 1/2 ton Silverado 4X4 with a 4" lift.  Truck has 157,000 miles.  The u-joints make the most awful clunking sound when I go on long trips with a bed load of camping gear. (At least I am pretty sure it's the u-joints)   I am afraid they are going to break soon.  What should I expect to spend for a u-joint replacement and is it worth it to upgrade to Heavy Duty u-joints?  Thanks, Wade

Answer
Hi Wade,
If you wait till the driveshaft comes loose while driving, it could be very expensive, as well as hazzardous.
If you replace them yourself, the cost of the joints is only about $15. each.
The lift kit should have taken the driveshaft angle into consideration, but if not, you may need to do something to ease the angles.
But if the joints are clunking, you need to do something pretty soon.
Good luck,
Van