Boost referenced Holley 850's by Barry Grant.
TheY are 4781's with the choke horns milled off. At least that is the number engraved into the main carb body.
Come with both original and chrome float bowls and acc. pump wells.
I got them as part of a package with a blower and have no use for them.
No idea what jets or PV's are in them. Never took them out of the boxes they arrived in.
They appear to be in good condition but I do not know their history.
$ 400 the pair plus shipping.