Hey Mart, I know where there's one 
That's a nice truck - mine is a similar colour.
I don't know what others think about that high a gearing, but I recently changed from 6.00-16 rears to 7.50-16s, and it has really killed top gear. It used to seem really buzzy with the banger at, say 50-ish, but now it seems to struggle with the jump from second to top. Now, I don't know what the ratio is as it doesn't appear to be stamped on the banjo like on the V8 rears, so it could be taller than your 4.11s, but I think I'm going back down to 7.00 or even 6.50s to bring it back to life.