... could potentially drop in a 1992 C1500?

I'm not racing perse, but hot-******* in designated areas wouldn't be out of the question.

What other things would I have to upgrade to avoid exploding parts on the road and would it help to lower the suspension etc etc?

Everything is currently stock. 305, 4 speed trans.

 

The biggest engine you can fit is most likely the biggest they make, the 572. I would recommend going to a newer LS series engine like the 5.3 or 6.0 truck motor for reliability and power

 

Here's a 6.0 stock bottom end with cam, head work, nitrous, and a few more things done. Its a 95 Chevy Ext. cab dropped with air bags. This just shows the potential of the Gen III LSX Motors. P.S. He got this motor from a junkyard for a few hundred bucks.