Dwmiles,
I'm a little unclear on your post: you mentioned the use of 6" rods in a small block, and then mentioned bore/stroke ratio. If you are talking about running longer rods and increasing your rod/stroke ratio, YES, there are benefits. Less rod angularity, less side-loading, more piston dwell, etc.
With big blocks with a 4" stroke (454), you can run upto about 6.535" rods, which are +.400" over the stock 6.135". If you run a tall deck block, you can run upto 6.800" rods, for a rod/stroke ratio of 1.7. Much better than the stock 1.53.
A higher rod/stroke ratio WILL allow you to run a slightly higher compression ratio with the same fuel before detonation, but I wouldn't say significantly more HP.
Something to keep in mind if you are buying rods and pistons, since they are the same price as stock in the aftermarket. I am currently building a 505 with a tall deck block, and I'm running 6.700" rods with a +.250" stroker crank. I'll let you know how it works!
If you were talking bore/stroke ratio, I misunderstood you.
Ryan
[This message has been edited by Ryan Hoskins (edited 12-21-1999).]