E70-15 were 26.73" tall and F70-15 were 26.51"
?????
You may have those two numbers transposed. The F 70 15 would have to be taller. I think everyone would agree the F is wider. If they have the same aspect ratio (70) it would of necessity, be taller.
It may be that one makers F 70 15 was slightly shorter than another maker's E 70 15, but if from the same manufacturer, the F 70 would have to be taller than the E 70.
I realize this is not an exact science, as it is impossible to convert letter sizes to the modern metric sizes with 100% accuracy. Heck, even two tires (from different manufacturers) might not measure the same section width even though both are marked as, say 235 or 245. There is a lot of "rounding" to the closest 5.
Assuming the E 70 15 is roughly equivilant to a modern 215 70 15 (and even that can be argued.... I would guess it is closer to a 210 section width, but others will disagree) I get an overall height of 26.55. The F 70 15, if it is assumed is the same as a modern 225 70 15 (which is very close) calculates to 27.5. Your mileage may vary.
Firestone says the FR60 15 is 26.1 inches tall (see here:
https://www.lucasclassictires.com/FR...RWL-62510L.htm) So, if there is a rubbing issue, it would be a result of extra width, not extra height.