With the acr power plus (head, carb, cam etc) it would be a good idea to upgrade.
Has anyone fitted the Salsbury to the short wheelbase as this would be the obvoius upgrade, I have one on the 2a 109 with 2 1/4 petrol with acr Power Plus and a couple of other bits (100 - 110 bhp depending on how it feels), 265 tyres. I haven't broken a shaft yet but have got spares for when i do (they have been in the garage for about 7 years now).