I have a pair of Birmingham manufactured SUs on a 240 manifold. Their serial numbers are AUD 425F and AUD 425R.

Any one know what they are origionally off.

I have been unable to find that model number in the SU book. Why do you ask? FWIW F & R stand for Front and Rear. Sorry I can't be of more help.

Lookslike 1970 MGB had them.

Somewhere to start

http://www.austinmemories.com/page130/page131/page131.html

http://www.sucarb.co.uk/ProductSearchResults.aspx?SearchTerm=AUD425

Edited January 22, 201214 yr by Blue

I have been unable to find that model number in the SU book. Why do you ask? FWIW F & R stand for Front and Rear. Sorry I can't be of more help.

Thanks Bruce.

I wondered why someone would bother putting these on a 240 manifold, unless it was a replacement for the flat tops.

Some good information there Blue. When I am fully awake I will read it fully. Thanks.

Brian.

Not exactly what you want but close... with some good spring data at the front.

http://www.tr-freun.de/triki/lib/exe/fetch.php?media=vergaser:su_butec_1969-1983.pdf

These MGB may be an oddity at 1 3/4" and are HS6 an equivalent to the 46mm Hitachis. The Burlin book I have shows the 70s MGBs ran HS4s or 38mm carbs on the 1800. Right thru that series the SU numbers I see are all right in that range. I just don't see AUD 425.....

Hi Bruce,here is where I found the MGB references:

http://www.team.net/archive/mgs/2000-06/msg00861.html

http://www.team.net/mharc/archives/html/spridgets/2001-03/msg00950.html

Thanks Guys. Looks as though they are 1970 MGB

The link Austin memories is interesting Blue. Lots of good information.