If it doesn't have a switch for SSB, I wouldn't recommend you use it for SSB. You'll have a lot of relay chatter, and most likely the amp is not properly biased for SSB... you'd probably sound pretty nasty on the air.
The amp can be modified for SSB delay AND proper biasing, up to you on what you'd like to do. If SSB is your preferred mode of choice, I'd just look for an amp that is properly setup for SSB use. Good luck!
~Cheers~