So you're saying that "215 (on 15" rims) are about 1 1/2" shorter in diameter" (than 16" wheels w/ stock tires)?
The 215’s are approx 1 1/2 shorter in diameter than the 235's on the 15's.
I believe the stock diameter is 29", but maybe a wheel and tire guy can confirm.
caculator In my view the 215's on a stock height truck and springs would not look right.
The tire would not fill the wheel well. But that’s just my opinion.
Good luck