I have just been given a 1979 Chevrolet 1/2 ton pickup. It has 78k original miles. Runs great now, after a little work at a local shop. It sat for 5 years in a garage. The only issue left is shocks and struts. The truck really bounces along and I won't be able to load anything heavy until I get this addressed. I will use this truck for farm work and it will need to handle heavy loads. What do I need to look for in a shock or strut to maximize its potential?