I currently have 235 x80 r 17 tires on the front and rear - the F3 is not on road yet but a test drive has the front rubbing slightly when I turn . If I check sizes these are 31.8 inches high 9.25 wide with a 7.4 sidewall if I go to 225 x 60 x 17
they will be 27.6 high 8.86 wide and 5.3side wall

That looks like a 4.2 inch height difference - will I really gain 4 inches or half of that or will it be less because of springs etc.????
It may solve the wheel problem for me.

 

sounds like a wheel offset or track width issue, my F3 stock had 34" front tires, plenty of room for them.

 

I should have said I have a Jag front end on it and spacers for the 8 bolt wheels -- I bought the wheels 10 years ago to dump the widow makers -- using Am Racing ATLAS 160 wheels. The spacer is what is causing the problem and seeing this will be (if ever finished) just an occasional used truck I'm not too worried about using spacers to go from 5 bolt to 8 bolt. 2 Tires would be a lot cheaper that 4 wheels.

 

Changing the tires will lower the truck 2.1 inches (or very close to it). Also you will have a higher gear ratio so your speed for a given rpm will be lower. Here is a calculator to figure speed and rpm.

Gear Ratio Calculator

 

I only plann on changing the front 2tires - It makes sense the truck will be lower but it should not make a difference on the speedo as that is running of the rear unless I am really lost & confused- which is the case most of the time-- The real question that I can't get my head around is will it give me more room between the tire and the fender? I would think it should give me at least half the size difference or about 2 inches which would give me the clearance I need. But just not sure if that is true. As the funds for this has way exceeded the budget (I am sure that is true for most all of us) I hate to buy 2 tires just to find out it doesn't work. Thanks for input so far I do appreciate any and all of it but I still just not sure this is a valid assumption. dave s

 

You are correct on the speedo - it is driven off of the trans so only the rear tire size affects it.

As far as the clearance, you would get 1/2 the height difference saved between the tire and fender edge. Therefore, you will drop the front by about 2" and gain 2" clearance around the circumference of the tire.

If you are still nervous about dropping the $$, you might look at a tire shop and let them know what size tire you are looking for and tell them it is just for mock-up. They may work with you and give you a worn out tire that someone swaps off for new so that you can test fit it.

 

Thanks Dmack I will talk to the tire guys - it's worth a try. If I get the 2 inches I save a bunch on the wheels plus I just like the look of the ATLAS wheels on the truck. The style looks like they belong on an F3. dave s

 

Good luck with it. I was lucky and was walking around the neighborhood and saw a neighbor had a 235/60/15 lying outside his shed. He said I could mount it up to test fit it. That allowed me to see what I would have for clearance front and back. Worked out well.

I have a HF manual tire changer, so it didn't cost me anything to try it out.