Well, you might find having 2 different patterns a problem if you ever get a flat tire! I think you can use 49-54 spindles, brakes, etc... on your '48 if you want to change over to 5 lug, but I have never tried this, so not sure about the details. Consider upgrading to a dual master cylinder also.
Did your 235 originally have an automatic behind it? if it did, it may not have provision for a pilot bushing in the end of the crankshaft. Check on that before you go too far with it.
also, 12 volt and 6 volt systems used different tooth counts, so don't try to mix the 2 together. You can use the 6 volt starter on 12 volts if you want to.
[This message has been edited by gearhead (edited 02-06-2003).]