Hi,
I'm a general vehicle nut & grease monkey, but I am at present researching 'special' engine #s used by BMC in prototypes, works race/rally cars, FJ/F3 & significant engine mods. These are mostly prefixed XSP (Experimental Special Products, Morris Engines, Coventry), EX (MG), CEXP (seen on works Landcrab) & SPL (Special Products Longbridge).
I'll post details in another thread, but am unsure whether to put it under British vehicles or research section; please advise!
Rob