is that is se cable or indiual conducters?? and how long the run it is ?? basically #4 al wire are run about 60 to 80 depend on what cable you have .
P.S. a quick short cut #4 al =#6 cu it will be almost the same
if you have 60 amp main fuse or breaker that will be correct size but use 100 amps you are pushing your luck with it for 100 amps really require #2 al anyway or #3 cu