Short answer, nope, not really.
Longer answer, shocks don’t increase rear spring rate. Bags, new springs, add a leafs etc do.
Even longer answer is a question. Considering the only TCs that will even physically fit, weight aside, are small pop ups and very small hard side campers. Hard sides most of which available are from small very expensive “boutique” mfgs that make campers they claim are for over landing. The question is, are you good with less space and possibly less features than you old pop ups? For a LOT more money?
If not, then you absolutely have the wrong truck for a TC.
You may find the odd, old 6 pac or similar old dinky hard side for cheap. And little pop ups can be had for $10k+ in nice condition. But maybe think about your wants, needs and how much you love your current truck if you are thinking you’ll find a full featured TC for a mid size truck, that has similar and tires to a micro mini size TT.