Try www.piercemanifolds.com here in the States for A-series Weber manifolds - they have kits available for single or dual Webers onto A-series engines.

I just purchased a single Weber intake for an A14/15 from Ebay - the manifold was listed as being for a Datsun F10/310 front-drive application, but clears header nicely! This is an oval port manifold & it came from Pierce -

I don"t know for sure that I will be using this manifold, as I also have a twin Weber intake for an A-series & am looking to go the FI route by using the fuel injection rack from a late-model Suzuki GSX-R 750 & go with a Megasquirt controller -

regards,
Bryan

Well if your not gonna use it, send it to me

Seriously i'll buy it off ya if you don't want it AND you're willing to post to Australia

you have other options MadTimo. You could:
a) fit the A12 head to suit you manifold. with a single sidedraught carb there would be little loss in performance. different story if you are planning to use the same manifold when it's turboed though
b) if you want to keep the oval port head, just cut and shut your sidedraught manifold and the standard A15 manifold. Choose the point where they would best align, cut it and get it TIGed together (bolted to a head of course) and 'port match' the two halves internally.

I did this a few years ago with a twin SU manifold. I found the best place to cut the standard manifold was just behind where the manifold separater is for the ports. Any further upstream and the manifold is a bit too small and restrictive.

I looked for a long time to find a factory A-series twin SU manifold, but no luck. So I did the next best thing - took an A 14/15 manifold & an MGB 1 1/2" manifold & combined the two - made my own twin SU intake! TIg'd them together & they look fairly stock...

Bryan

"Oh, Bother!" said the Borg.
"Crap! We've just assimilated Winnie the Pooh!"