351w

i run 275-70-15 on my truck and it works really nice but i also have mods done to increase my HP.
actually i find that the 275's are wider and a little heavier than the 10.5's that i had before.
i prefer the 10.5's and i am looing around right now at buyin a set before snow starts falling.
also i have to say this to DUCKY i would not recommend myself putting that size tire on a 4 cyl or 6cyl bronco or explorer but this is an F series post and the parts used on the F series trucks will hold up alot better than an explorer would with this type change.
my truck is an 86 with over 150,000 miles on it and i never lost a tranny or rear but then again i take care of them and change fluid in them.
but oversize tires will add wear for sure.

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i would rather push my Ford than drive your Chevy !