Technical 63 nailhead

Hi
i picked up a 63 nailhead 401 over the weekend,lookslike a 325 horse ,hipo
it alos came with this manifold and carbs attached
any one have any ideas what it is

thanks
John

 

Look up # on bottom . #5091 is an Offenhauser , so maybe #5191 is as well.

 

anyone else..?

 

still looking for anyone that might know who made this
thanks

 

Offenhauser it is, by "magic" of Google:

https://www.summitracing.com/parts/ofy-5191

Intake Manifold, 360 Degree, Dual Quad, Aluminum, Natural, Dual Square Bore, Buick, 401/425, Each

Estimated Ship Date: 7/29/2019 (if ordered today)