In ALL timing specifications there's NO difference made for the different speed versions. E.g.: t(WHLH), which is '/RD or /WR high to ALE high', is specified as:

t(WHLH) min = t(CLCL) - 20ns, t(WHLH) max = t(CLCL) + 25ns.

So, my conclusion:

If in datasheet in specifications it's NOT distinguished between different speed versions, then there should NOT be a problem.

As I stated in an earlier post the difference that DOES exist between "speed grades" is rise and fall times.

Erik