bluC20, what size rim do you have now? I'm guessing it's a '63 C20? I have some Denman bias plies on my '65 C20. They are 8.75-16.5. I had 16" steel rims but, couldn't find any good sized bias in 16" that were an appropriate weight rating. They were all too tall or too short or too skinny or too wide. Believe me, I looked long and hard. The radials I looked at, the LT's, were too modern looking for my tastes. I do like the way the Denman's look but, compared to the radials I had, they ride like dookie. I've had them balanced twice by two different places. The 2nd time was an improvement but the truck still shakes at higher speeds. With the radials, it was smooth even at 90 mph.
That being said, when I switched to bias on my '54 Pontiac it was a huge IMPROVEMENT. Steering was easier and I can drive 70-75 mph no problem.
I've never heard of speed being much of an issue with bias tires. Mostly just the fact that they tend to grab and follow the little grooves in the freeway.
Based on my experience, can't say I'd recommend the Denman's. Perhaps I got a bad batch, don't know.
There's lots of bias tires available, you just have to do all the legwork. I couldn't get any dealers to help me out and realized after a bit that they didn't know anything about light truck bias anyways. You've got to do the legwork and then call them for a price or just order online. I can point you to a couple places if you'd like.
