Hi, got one in my panel van, and it's great. Van will sit on 50-55 mph no problem (screaming a bit but it's OK). Still good around town and makes first gear usable!! Not exactly sure of my tyre size, but I know they are the same rolling diameter as the original crossplys. I think they are 185/75R15. I am running the Hunter GT spec motor, but the 4.2 ratio was fine with my old standard 1725. As my original ratio was 5.6:1, the 4.2 means that my miles to kilometres conversion is much easier as well - just double the speedo reading.
Hope this helps!