Is your engine 4 cylinder (220 cu in) or 6 cylinder (330 cu in)?
The two engines use most of the same internals eg pistons, valves, rods, rockers etc. The bits that are different are the 'longitudinal' bits eg, crank, camshaft etc, and obviously the castings.
There should be plenty of mechanics with experience of Bedford engines (even though they are no longer in production) and plenty of parts available to fit if necessary.
Search the internet using '
Bedford 220/330 turbo' and contact your local breakers yards such as:-
Mirfield Auto Spares
Lowlands Road, Off Station Road,
West Yorkshire
WF14 8LX
Telephone:
01924-495085
My experience was not with engines, so I cannot personally help you, I'm afraid.
Manual supplement available here:-
http://www.greenmachinesurplus.com/b...itre-641-p.asp
Engine available here:-
http://www.alibaba.com/product-free/...20_Engine.html
See also:-
http://www.gobookee.net/search.php?q...+diesel+engine
It might just be a Perkins Phaser engine:-
http://www.gobookee.net/4cly-turbo-p...diesel-engine/