That's the same tread style as some old generic mud tires we ran on a '72 40. They wore very well, but didn't stick worth anything offroad (we just thought that's how all tires were until we got to some BFGs and MTRs, wow those stuck alot better). They did good in mud as they are big and open. I don't know if the tread compound is the same on these Dunlops, but the style is the same. Did you have them siped? I would be tempted to sipe them by hand...but even if they are the same tread compound the 80 is alot heavier than the 40 was, so they might give plenty of traction anyway.

