Mr Plowboy,
You can insert a latemodel flatty with later truck pumps 48-51 and a lower pullie out of the same truck. You'll have to shave one pully as it only came as a double (well I never seen a single). Its easy and you don't have to ratrod the firewall
. You pedal set up for juice brake are a easy one , just make sure you can get the pedals
Thanks