play around with this link on tire sizes an see just how much a tire will change your highway rpm's. on my 66 i run 235 x 60 15's but i have a 700r4 an run 2200 rpm's on the highway with a 3.55 rear. will a 3.36 rear fit, i think that's the number ?

Gearing Calculator | RPM and Tire Diameter to km/h - mph with Shift Tracer (blocklayer.com)

 

got it! I use the Wallace Racing Calculator mainly. A 28" tall tire will drop my RPM by 300 - just curious how tall of a tire will fit... wont switch gear. Your info is good to know since we have the same gear and tire.

 

the problem with using tire to drop rpm is it doesn't make much of a difference as you see with only 300rpm drop with 28" tires
then there is what is meant by fit, this is a personal thing
even 28" are not going to fit if you want car close to level and a decent ride height with anywhere close to stock wheel wells

plus you would have a hard time getting 28" tall without being too wide

look around this site for pictures, most of the cars that have the max width for the wheel well are using somewhere between 45 series 17" to 35 series 18" to get the width they need and keep the tire from getting too tall

there may be someone on here that knows of the perfect tire wheel combo that would get what you want

but in my experience, I don't think you can get both

plus you have told us nothing about your engine, that can really effect what is a good cruising rpm

edit: I just looked at tire rack, BFG does have 225 to 255 in 70 series 15", these are 27" to 28" tall
but with any of these getting the ass end sitting down at all may be the issue

 

Great points! I have coil overs and a 4 bar set up out back so getting the rear level is much easier for me as I can drop spring heights (or swap coilovers if springs wont do it). I'm trying to only get tallest tire in a stock fender well so that's why I left motor info out (I guess I could have left out the trans and gear info as well as that doesn't help me get a tire height). Tracking on Tire Rack with 28" tall tires for 17 and 18" wheels. Hoping someone is running 28 or taller... Thanks for the post!

 

but you are asking questions that no one can answer for you, that is what I meant by stating fit is a personal thing

you will be able to fit 28" tire with the rear high in the air
you will not be able to get the below look with 28" tires, without going pretty narrow tires

these tires are about 25", you will be 1-1/2" higher just from axle height

 

but you are asking questions that no one can answer for you, that is what I meant by stating fit is a personal thing

you will be able to fit 28" tire with the rear high in the air
you will not be able to get the below look with 28" tires, without going pretty narrow tires

these tires are about 25", you will be 1-1/2" higher just from axle height

View attachment 437539

but you are asking questions that no one can answer for you, that is what I meant by stating fit is a personal thing

you will be able to fit 28" tire with the rear high in the air
you will not be able to get the below look with 28" tires, without going pretty narrow tires

these tires are about 25", you will be 1-1/2" higher just from axle height

View attachment 437539

I feel like "fit" is mechanical and look is "personal". Your comment about the axle tube being higher with a taller tire helped me determine that I need to measure the distance from the top of the tire to the top of the fender well and then subtract out the 4" of travel I use with my coilover suspension. Thanks! I think I'm on it now!

 

here are some more examples
first pic is how I bought the car, rear is high as wheels are too wide, but it would need to be high to fit 28" tires inside wheel well
second pic is after fixing the abomination and has 24.7" tires

 

I am building a 67 right now and I believe the tallest you can go is 26“ without jacking the back way up like was noted above. The place you need to look is the wheel opening front to rear. That distance is limited. So I run 26” as I have my rear lowered. And btw my rears are mini tubbed.
Rob

 

This is a 275/60 17 which is 28” tall. It’s not so much the height, it’s the front to back in the well. These are just rollers on a narrow jeep wheel with spacers, but it is practically touching the front of the lip. I’d say a 27” tall would be safest not knowing all the details of your rear setup.

 

Thanks! This helps! I have a TCI 4-link so my axle is centered between the "pinch points" and from left to right.

 

The biggest diameter tire that would fit in my tubbed 66-67 rear wheel opening without stretching the opening was 29".

28" looked better.

 

Ride height has a lot to do with wheel opening clearance.