The original propshaft from the BW35 auto was modified by changing the output sleeve yoke to a type 9 version.
It was considered at the same time to lengthen the propshaft by 1" - but the company I used (
autoprop-uk ) had recently had some items lost in a fire and couldn't do the balancing. So we just changed then ends and spiders.
I decided to wait a while to determine if all was well before going to adjust the propshaft length.
It later occurred to me that a spacer on the axle would be a solution. I wasn't sure if it would be "safe" until I noted a few "propshaft spacers" for land rovers and Atlas axles available on eBay.
So here is the drawing for the Sunbeam.
Lofty volunteered to make it.
A week later and here it is - and it fits! (amazed my measurements were accurate but lofty made compensations for my lack of tolerances )
Perfect fit on the propshaft, slight interference fit on the Diff flange as I made the measurements the same for both sides. M8x50 class 8.8 were used as the 5/16" x 1-3/4" UNF grade S were just a little too short to fully fit the nylocs.
A test run proved it hasn't added any balance issues and I'm happier the propshaft fits further onto the gearbox.