Largest Stock Tire Size For 72 K5?

[DANL]

Hey Members, I am considering buying stock 16" wheels like bouncy has. I want to determine if 16" wheels came stock from GM on the 72 K5 and if so what largest stock tire option was offered. I need this info for the following two reasons:

1. I want to install the tallest tires option GM originally offered but do not want to worry about rubbing.
2. COSTCO will not warranty tires if I can not provide GM data stating this size tire was an original stock option.

Any help would be appreciated.

Thanks in advance.

...Dan