The only experience I had of Rollers was the 265L in our B-series ERFs. These were bought due to the price and the poor availability of “decent” engines. In my experience they were as good as any for the size and class and the only reliability issue we had was with the oil pump idler in the timing case which was located by a roll pin. The pin would occasionally shear if it wasn’t fitted properly, leaving the poor old driver with zero oil pressure and 100% of the blame!
As to the Big J, at the time I could find no fault with it- I soon got used to the offset steering column and, like others, I learnt to change gear without breaking my fingers on the dashboard! We had a whole fleet of the things at our branch of BRS (sorry for the bad language, Bewick) which were sourced as replacements for the AECs which we had all loved. They were all fitted with 205 ■■■■■■■■ such vast power in the day- with six-speed AEC gearboxes which had a fantastic air-operated inertia brake. I found this feature by accident and spent the next couple of months educating the other chaps who had been complaining of “slow gear changes”. After running-in the engine (remember that?) I called at Guy Motors workshop at North Woolwich and got one of the fitters to reset the injectors, slipping him a ten-bob note to “open it up a bit”.
I never had a moment’s bother with the Guy and I was quite sad to pass it on to another driver when I got married and moved away from the area. When I returned a few years later I was allocated another Big J which I was also pleased with, although it never went as well as my original.
In my opinion Guy’s were a great firm to deal with and it was a devastating missed opportunity not to have developed the Big J into a modern lorry.