Inlet rubbers for 501

[Steve Brown]

Hi folks, tried to fit the carbs to a 501 engine today and found the rubbers I have are for a 478 type head. Mdina website suggests they are the same part-surely shome mishtake here? There must be a good few millimetres difference.
Talking here about the carb to head rubbers and not the carb to airbox items.
Anyone got a couple to spare please?

[3potjohn]

I got a pair fairly recently for my Coguaro and I thought these were the standard 500 type. This for PHBH carbs.

[Steve Brown]

Yes, PHBH carbs John. The metal stub in the head is visibly larger and I haven't tried (too) hard to force the 478 types on there.
I'm asking for trouble really-mix and matching an Excalibur 501 with bits from a Sei-V engine to go first into the Sei-V and ultimately into my Camel Mk1/2 Wannabe/Hybrid.