Thanks to info from this forum and with tips from Capt. Bike (RIP) I was able to change my 6 speed 13-23 Uniglide cassette to a 13-28 (13-15-18-21-24-28) which my Dura Ace 7400 rear derailleur works fine with.

My bike came with a set of 53-42 (130 bcd) front rings which I am changing out. I have a new 38 and I am thinking of a 48 or 50 outer ring. What would you suggest?

I have also been contemplating trying the cassette ( I have enough cogs) as a 13-15-17-19-21-28 with the 28 being a bailout gear. I am not sure how well the RD will handle a 7 tooth jump. What do you think?

Thanks