largest tire size?

L60 15s
which would be about 275 60s
depends on the rim

68 barracuda
318 904 7 1/4 2.76 gears open
they fit and they did smoke-both even
OK it did take a bit to get them going-quite at bit accually
when we were getting it around the first time me and my dad was at my grandparents shop
he takes it out and smokes them
my grandmother(his mom)comes running out thinking the car was on fire :)
she should have known-all she could do was shake her head and walk back inside