I will, Phil - thank you. I’m going to look into whether there are modern sealed gel 6v batteries that will fit.
I have the exact same set up as you. And likewise noticed the slower turnover speed with a high torque starter compare to my etype. I have brand new 2x6volt lead acid batteries with fully rated cabling. My deduction is just the simple volt drop over the length of the cable. I’ve not measured the voltage at the starter on cranking (my arms aren’t long enough :-))
With best regards
Philip Dobson
I used these as they are the only company Thant will post ‘wet’
With best regards
Philip Dobson