I'm not sure if there is a difference in the two alternators or not. Mine would also crank a little slow sometimes. The voltage regulator died a slow death, so it was intermittant for a while. You may even try hooking it up to a battery charger and see if your signals speed up. Also, if you've got a meter, measure the voltage at the battery while @ idle. Should be in the 13-14V range (has to be over 12.6 v).

'91 LWB, 31x10.5s, KYBs, A/T "I look like Robert De Niro, I drive a Mitsubishi Pajero" - Billy Bragg (not the original lyrics, but that's how he sang it when I saw him in Dublin in '04)