i just bought these an i find the secondarys have a blockoff plate which lets no fuel into main body anybody ever heard of these plates?

Do you mean the "secondary metering plates" that are held on by 5 clutch head screws? they do meter fuel & I think the holes are in the bottom (I'm not a holley guy).

your right rr thanks for your input ill have to adjust my bifocals

just got my 1st pair myself. You can drill/tap the back side of the flat in the right location & use jets so you dont have to have a supply of diff plates when you get to where you're fine tuning the secondary. Actually it's not complicated as they simply used plates with diff orifices as they were much cheaper in mass production than a metering block. Trace the passages on the front side & you'll see where to drill. Cant remember exactly it's been quite awhile

Not to hijack the thread here, but what other base plates will fit the 660's. I have a set that have been sitting for years, and the baseplates are corroded pretty bad, useless I think. What others can be used cheaply???? Or am I up the creek?