tire sizes
 

My 69 C10 currently has 255-70X15 tires front and back on 8" wheels. I've been looking at ways to reduce highway revs a little w/o going to an OD trans. Axle ratio is 3.08, so there's nowhere to go from there.

What do you guys think about 32x10.5x15 tires in the rear? Looks like they will reduce RPM by 240 RPM at 70mph. I'd probably put the same brand/model tires on the front in size 235-75x15.

How would the truck look? I can handle criticism fairly well. :)

BTW, the engine is a mild 350 with TH350 trans. I am not worried about "getting off the line" in a hurry.

Re: tire sizes
 

I just did 31x10.50-15s with a a 1” drop front and 3” drop in rear. If yours isn’t dropped, you should be able to fit it.

Re: tire sizes
 

That's about how much mine is dropped. Thanks for the picture. Got any from an angle, like left front, right rear, etc?

Here's how mine looks now with 255-70x15s.

Re: tire sizes
 

Easiest and cheapest way is to reduce speed to 64 mph. A 6mph drop equals about 240 rpm.

Re: tire sizes
 

Problem solved! But then they'll call me "Slow Lane Charlie".

Back in the days of 55-65 mph speed limits, I put several thousand freeway miles on the truck. Heck, now a 70 mph speed limit essentially means 75-80 here in Texas, which the truck simply doesn't like.

Funny, because I remember driving freeways in cars with 27" tires and 3.7x gears back in the day, and we never even thought about needing another gear. Had a friend with 4.11 gears in a 60s Corvette who used to drive a 500 mile round trip twice a month to see his girlfriend. He said the same thing -- he doesn't remember the high revs being an issue.

Heck, I'll probably just end up with an OD trans, but then my 3.08 gears will be a little tall. Damned if I do...

Re: tire sizes
 

Here’s pictures before I added a 1” drop block in the rear, so it just has 2” drop coil in rear and 1” in front.

Re: tire sizes
 

What's that white stuff on the ground???

Re: tire sizes
 

Why not pick up a pair of cheap used tires off Craigslist or a wrecking yard and give them a test then if your not happy you're not out any serious cash.

Re: tire sizes
 

Thanks!