I used to get 60 and some out of our regimental RL with basically the same lump and crap carb
was enough to get from Brum at eightish and on an LZ at Thetford by half eleven ish, before they invented the A14
Mind you, no slowing down allowed even round the pair of 90ºs at Kimbolton
Just takes practise with the "behind your left buttock" gearchange
Err, JT Leavesleys near Alrewas on the A38 east of Lichfield often have Army surplusss reconned engines available, onnapallet ready to drop in the 'ole.
Want me to pop along for a butchers?
might talk the sweet lady into a drive out that way
bill