Some have an inlet and outlet on one of the float bowls like in the picture, others have a feed tube with a "Y"

I took them apart last night; one in good shape the other not so good. The rebuild is straightforward enough, I'm just struggling on how these link together from a plumbing perspective (can't find any references or pictures).

From the comments here it sounds like the weber may actually have the correct manifold. I thought it was wrong as it extends through the firewall....good news is now I can go to the single gauge, which I strongly prefer.

Spank- I'll email you over the weekend and we can discuss

I did some dyno testing comparing h2's to h4's. With "M" needles and 26 deg total adv on my 67s. The motor made 74.5 HP at the wheels with the h2's and is very drivable at all RPM's. The h4's made 7hp less. I was talking with a buddy who is a good "A" engine builder about my findings that the stock setup turned out to be the best choice. Not even looking up from his work bench he replied "They did do there home work at Longbridge".

I have 2 sets of new hs2 carbs on manifolds (fitted then removed within 500 miles and sitting in a box for the last 8-10 years), a rebuilt set, and various manifolds and carbs. Not interested in selling outright. More interested in using them as trade bait for your shell.

That said-- If you aren't worried about originality, I'd advise a single HIF44 / HIF6 (1-3/4" carb). 100hp (at the flywheel) for a modified street motor with a stock carb and proper needle is commonplace.

+1 with Spitz. HS2's.

I'm with Spitz on this one.  The Weber is cool and probably standard issue for track cars.  But to work best they need long manifolds - which foul the firewall right at the speedo opening.  So, on a street car one would have to opt for a more or less crappy manifold so the DCOE doesn't hit anything. 

Stock SU's work really well and you don't have to fabricate a bunch of nuggets to complete the installation.  Although, tracking down the proper S bits to complete yours might take a bit of time.  Embrace the treasure hunter inside you

Twin HS2 would be the correct carbs for a 1275 S ( factory ).  And are much more "proper" than a Weber...lol

The 1275 engine I got with my car came with two separate carb options: a twin hs2 (missing intake manifold and linkage) and a weber DCOE 45 (with the wrong intake). From what I've read the hs2 may be too economical and the weber may be too aggressive. Thoughts?

Tuning will be primarily street.

Based on the response if anybody has an intake for either set they'd be willing to trade for cash let me know. More $$$$ out the door.