What was the factory wheel size on a 73 highboy?
 

Did the 73 F250 4x4 come with '16 or '16.5 wheels?

8.00 x 16.5 tire size was likely standard,maybe 9.00 x 16.5. I don't think 16" wheels became standard until early 80's?

A good question might be what was the first year ford offered radial tires on trucks as standard equipment...LOL

FE406 is right, 6500 gvw 1973 f250 4x4 came standard with 8.00 x16.5 D tires with 16.5 x 6.0 rims.
optional 7100 gvw came with 8.00 x 16.5 E tires
optional 7700 gvw came with 8.75 x 16.5 E tires

Thanks. The P.O. had worn out 6.50x16s on it which look good on the highboy but I swapped on the new 8.75-16.5s off of the two wheel drive parts truck and they look too small.

I have seen quite a few 250s come with 16" split rims back when they were new. I worked for Goodyear and took many off for larger 16.5 rims.