I am looking to upgrade the wheels on my '63 Dynamic station wagon/hearse and am looking at low profile tires which don't seem to readily available in 15 but do with 16s. My question is, would increasing the wheel size by 1" cause any issues with handling,etc?
Any and all advice is greatly appreciated!

 

No, it will not effect handling, wheel size is not what determines the change, tire diameter and width does. It will however possibly effect ride quality with shorter sidewalls.

 

ASSUMING that the 16" tires you are planning on using are the same outside diameter as the 15" tires you currently have on the car, the only difference from the larger wheels will be the shorter, stiffer sidewalls. This will reduce sidewall flex during cornering. It will also reduce sidewall flex when you hit a bump, making for a harsher ride. More importantly, are you looking at tire outside diameter? Most low profile 16" tires are considerably SMALLER in outside diameter than 15" tires. Your 63 Dynamic hearse is a heavy car. Your suspension is soft (unless you've modified it). It doesn't have a rear sway bar. You'll likely see zero handling differences, and will feel the harsher ride. The original tires on this car were a little over 27" in diameter. You'd need a 235/60-16 or a 255/55-16 to be close.