...I think someone said 3.1.1 was the last version that they worked in, I did not test it,...
Just to clarify. Guess it was my guess and I was wrong. --icarus-timing short and --icarus-timing long still working fine with latest cgminer versions. Mea culpa. But back to topic. 
yes with the latest versions 3.4.1+ the timing option does work and an extra option has been added. i use --icarus-timing short=90 which gives me 447 on all the 16Mhz units.
it also stops the timing issues is the PC has issues which running short.