67 C10 Air ride with leaf suspension questions

[furburd]

I have a 67 C10 with leafs in the rear, I mostly read about trailing arm coil spring suspension... Can someone answer a few questions I have?

1. Were there multiple rear suspensions produced in 67 and/or is mine stock?

2. Because I have leafs, do I need to go to a 4 link in order to put air ride on it?

Looking for a low cost solution to improve ride and drop it a little on demand. Looking at ride tech level 1 but looks to be for trailing arm coil spring suspensions.

Has a bbc, 2.5in drop spindles, and pulled a leaf or two out to level rear.

Any other advice appreciated.

Thanks.