The 763G also has a larger engine. I still like my 743, very simple to use and work on. The 763G as mentioned can be rather complex depending on what features it has. All the senders are more expensive than the 743, quite a bit actually.It depends on what you're going to do with it. The 743B is a very simple machine to maintain(no electronics) but only has 11gpm. The 763G has lots of electronics and came with several different controls systems(ACS hand, ACS hand/foot, AHS and AHS with float). and 16gpm standard, 26gpm high flow.
Just sold my 763G and kept the 743B. I have a soft spot in my heart for it. It was my father in laws pride and joy.The 763G also has a larger engine. I still like my 743, very simple to use and work on. The 763G as mentioned can be rather complex depending on what features it has. All the senders are more expensive than the 743, quite a bit actually.