It's a 7.5:1.
If the GPM really is 7:1 (according to google) then I wouldn't think it would be any quicker, but it might be smoother if it's lighter.
Having said that getting the bottom end set up really well seemed to have a big effect on mine.
(How odd, there was a 5045 just like that on ebay not very long ago!!)
'55 Huntmaster, '56 VH, ' 51 VH, '80 R100RT, '00 Sprint ST (but all those Ariel parts can only make one running bike...)