leaving the 11.1125 crystal in there will give you 26.175-27.455 i believe.
the 11.3258 crystal would give 26.815 to 28.045.
just so you are aware, your radio will need an alignment afterwards no matter what.
the VCO will most likely need a slight adjustment.
you cant do freq mods without a real frequency counter.
sure, you may get lucky and only be off by a marginal amount, but you wont know whether it worked or not without the counter.
also, the radio needs to be realigned after the freq mod or you wont have good sensitivity on your new channels.
if you are determined to try this, here is a link to a mod that uses the 11.1125 crystal and claims to get the high range also.
BE WARNED!!!!!
i have not tested this mod, and it came from Secret CB which is well known for its many mistakes and typos.
http://www.cbtricks.com/pub/secret_cb/index.htm
my opinion is that you should NOT try it, but i always post the info anyway.
LC