You shouldn't cause any damage to anything by putting the wrong SIMM in it, it just may not be able to address all of the available memory on the chips, possibly giving you a result that is lower than it should be - either that, or it wont work at all. The worst this could do is destabilize a system...
Correct.... Provided you don't jam in an improper SIMM (indexed differently, etc) or physically break your SIMM mount (some are fragile in old age!) you shouldn't damage anything. Especially not the card. If anything, the risk is on the SIMM (if by some strange chance it's a lower voltage, yet still indexed as a normal voltage - might happen in a specialty SIMM designed for a printer, or something like that, but very VERY rare.)
Now, it won't guarantee that you'll properly identify a SIMM module, though. As stated, if it's larger than your accelerator supports, the SIMM will be misdetected, and the system probably won't run stable.
The best way to identify a SIMM module may be to type the chip code into google and see what comes up. Start reading and following links from there. I've done that to identify ZIP chips before...
