[Healeys] HS4 float lid conundrum

[john spaur]

I have a set of three S.U. Carburetter tops with part number AUC 1433 
cast into the top. Does anyone know what model carburetor these are used on?

On the AUC 1433 tops I can set the float lever to 5/16" per the shop 
manual by using a metal fork and a brass float. However, when I 
compare the lid and brass needle seat to another set of float tops 
marked AUD 2277 (on the inside of the lid) I can see a difference in 
the needle height. The best way to describe it is the brass portion 
of the needle seat is about 3/32" higher on the AUC 1433 tops than it 
is on the AUC 2277 tops. I can not lower the needle seat on the AUC 
1433 tops but I could adjust the float lever to compensate - I think.

Would that work or does it make a difference.

BTW, are the AUD 2277 tops correct for a 1962 Tri-carb? They use the 
non-adjustable nylon float which, when installed is at 7/32" and not 
1/8" as specified in the manual. I can't see anyway of adjusting it 
because there is only one very thin (1/64") washer between the brass 
needle seat and the float top.

I can't test anything because the engine is not back in the car yet.

Help!

TIA,
John Spaur
San Jose, CA