BRAKES WHAT'S NORMAL

[Bob Culver]

Hi Peter

That combination is mentioned amongst all the previous above and perhaps on another recent Thread. Repeating for completeness.
Quite apart from lever length, the Girling have more leverage ie more angular travel for the same shoe movement.
The different cable line with Girlings does not help; brake cable should move in much same arc as axle, otherwise braking varies with load and bumps.
I convinced myself with my RP with Girlings that the cable would not pass under the axle as on  low Ruby and/or angle too steep so fitted the levers facing up ( cams maybe interchanged) with the cables just over axle much as original RP alignment. (Except that offset laterally. ideally need relocated guide. Mine just run straight through unguided which is not ideal. This topic was covered extensively some time ago with photos from Ruairidh). 
New cables were expensive and the original fixed ones too short so I used the original Ruby cable and made up clevis extension piece. 

You should certainly have the long levers on front. I presume there are girling and pre girling and that both useable.

I suspect short levers on rear would cause cable to rub axle tube, esp if under as on Ruby. I guess some cup to clevis adapter could be devised

One occasion where front lead may not be desirable!