My 68 RR has the sticker in the trunk for F70/14 Uniroyal Polyglass raised white letter tires
it had the 14" Chrome Road Wheels org. from the factory too
IIRC there were called 'Tiger Paws' in the adverts, not sure Plymouth said that thou...
(Pontiac

references)
My parents ordered new in Nov 1967, mom's 1st ever brand new car
a GG1 1968 Sport Satellite, 383 4bbl 4 speed, had a dealer optioned (stepdad Bob wanted)
15" Uniroyal's raised w/l tires 70's front 60s back too, on Fenton Polished Kidney Slots
with dealer installed 3.91:1 sure-grip, rear axle package
with all the Org. 14" steel wheels, tires & full hubcaps
& factory 3.23:1 ring & pinion, in the trunk when we picked it up...