Bit late to this discussion but I have a 1980 plus eight, just rebuilt which does have Edelbrocks on an Offenhauser manifold. Came as standard from JRV8 who did my engine rebuild (after 238,000 miles). The car runs really well on them but lockdown since last March here in Leicester means I've not been able to do enough driving to get a good handle on fuel consumption. The old SU's gave about 25mpg. I'm only about thirty miles away from you, so if you needed to compare settings etc just let me know.
Welcome to TM from me too.
Tim
