Just bought a 3x2 intake setup that has Stromberg 97’s with “SP” tops on it. Now that I’ve got my hands on it and looked at it closely. I’m thinking they’re re-pop tops. I’ve never closely inspected a real one, so don’t have any knowledge to compare too. I’m told that the real ones are very nicely cast. And these look a little rough to me. But far nicer than the ones I’ve seen at car shows on the table with all sorts of other poorly cast not machined stuff. What says you all?
Those are the real ones. None of the repros have the SP logo on the top like that. However, the current available repros sold on eBay from time to time are die cast so they're much better castings than the original ones.
Those do look like sand cast. You might want to pull one of the tops to see what the underside of the bowl cover looks like. I bought a set of three for prime money. Brian B*** had to tell me I had reproduction pieces. Maybe this might help https://www.jalopyjournal.com/forum/threads/sp-tops-how-were-they-handled.542342/
That was the best thread I found when searching. And gave me the tip off on the sand cast ones with SP logo. Definitely some porosity in these, so guessing that’s what they are. Or just eaten up from the salt after many years of racing
My original tops have a far more rounded edge on top, but perhaps yours have been modified/flattened on top to make a better seal with an air filter housing…. Sorry best photo I have
I had one on a carb I built for a fella. It had the holes drilled for a screen of sorts. I used loc-***e on aluminum screws to fill them, then snipped off heads and blended them into the contour. Just a thought…
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