Haven't heard any reports back on the larger Blockley's - the bigger size was fitted to the "Death's Head" customised M3W that was at the factory for a while (might even still be there?) had the 4.50s fitted apparently but without the mudguards which might be a bit of a clue as to how well they fit.
I've been running the 4.00x19 Blockley's for a while now and find them very good indeed.
