This discovery of there being two different sized manifolds for the single
Stromberg is something I think we should try to figure out. There's a lot of
performance increase potential in this, while retaining the visual appearance
of having all the emissions configuration to keep the inspection weenies at
bay. I don't think there will be a tailpipe emissions inspection problem using
the larger runners. The inspection standards are so loose, compared to the
pre-production inspection standards, that I don't think this will matter. The
larger runners would help tremendously at increasing the higher rpm power of
the 1500, and probably the 1300, if the 1300 isn't the one with the bigger
runners already.
I can contribute that my 1980 federal Spitfire had the small runner Stromberg
manifold. It has the telltale stains at the head gasket end clearly showing
its reduced runner size. Double verified by sticking my fingers into the head
ports, the runners of my double SU manifold, and the Stromberg manifold. Yep,
it's smaller. I could have used a ruler to measure, but that would have been
so correct I couldn't stand it.
Now, staring at the Vicky Brit catalog, this manifold of mine was used
federally only in 1980, and is the 1978-1980 California manifold.
I can go no further, but can some of you folks put in some input into
identifying which Stromberg manifold had the larger runners? Once we identify
it, it would be a darn good hot rod FAQ for various Spitfire web pages.
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