If you have a PJK it would have been supplied with a Bedford 330 cu in six cylinder engine.

This might help you:- https://www.flickr.com/groups/1335348@N23/

Also:- http://whotalking.com/flickr/PJK

Alternative (earlier) designation VAS5.

Reg doc says 1998cc and has a five speed box any way of checking? Definitely a six cylinder diesel so doubt it's only 2litre

330 cu ins = 5.4 litres

Rob at bedford truck parts has given a breakdown of the chassis number.
P=Forward control coach,
J =330 diesel engine,
K=6577kg,
1=short wheelbase,
B =4 speed single speed axle
ZO =chassis only
FW=1976
Rest is the unique chassis number.

Odd why my registration doc only shows a 1998cc Diesel engine. Will get cover off and have a good poke around. My van has a 2.2 turbo so must have bigger for 7.5t

I suspect some sleight of hand when the registration was changed - why was it changed from LPB 116P to OGV265P?

4 speed gearbox would be Bedford's own gearbox (as fitted to some TJs and TKs).

Quick update to let you all know how it's going.
Have fully stripped out all the interior and caravan additions.
Will be selling all the original roof panelling and trims if anyone is interested or knows of anyone that is please contact me.
Still looking for someone to do a service and once over on the bus. Will be running all the electrics soon and then insulating all the interior.
Photos to follow.