1949 Bedford engine rebuild

I agree with Beaver. I think, generally speaking, distributors are driven from the oil pump, so if the drive to the oil pump breaks, the dizzy stops turning and the engine stops. Priming the system with a drill pump is far easier, you only have to change one fitting and it only takes a few minutes.

You've probably got her running by now but your lack of oil pressure sounds typical of a fresh build and a dry oil pump.
In the olden days one would liberally coat the oilpump gears with vaseline but not these days, we're a bit more switched on.
Where does all that vaseline go?
To the easiest main or big end and it takes a while before the engine oil can finally remove it all by which time a modern engine with nice tight tolerances will have ruined its bearing clearances.
Best option with any build is to use assembly lube on all your bearings and the oil pump.
Then remove the oil pressure switch and pressure prime the whole engine using engine oil.
This way you know all bearings are oiled as is the oil pump and the filter is filled too.
Remove your pressure gear and replace the oil pressure switch, pull the spark plugs and spin her over, you'll see oil pressure straight away.
No damage to anything.

Regards.

my lesson for the day is getting harder it would appear that after a quick look at google that not all bedford dizzys are driven they way I thought only some would appear that Ford Holden GM are driven the way I thought not Chrysler though but as I said at the start I dont no bugger all about Bedford's now I no a little bit more than bugger all and you all no what they say about a little bit of knowledge being dangerous watch out all you OH&S guys Im Dangerous seeya and good luck with the Bedford you should have bought a Mack
Paul

On Chrysler small and big blocks one can prime the oil pump with a 5/16 hex shaft down into the oil pump driven by drill after taking out the dissy and dissy drive. Falcon 6 is also like this. With other engines i prime them through the oil filter holes in side of block or were ever oil filter spins on. I use a drum pump and pump oil in while turning engine over by hand to get whole system full. Then put a full filter on it. You must have oil pressure straight away and once running keep at 1500-2500 rpm for a good 20 minutes to bed in cam and lifters, use a good amount of assembly lube on cam and underside of lifters. These are splash fed so at idle and slow rpm they don't get much oil. Use a mineral oil with zinc in it and drop it and swap oil filter after first run to get all the assembly lube out. Flat tappet cams/lifters are a thing of the past now and like everything these days are not built how they were in the good old days.