650 cfm(?) 6r4585B
80145 d240. What is the intended use? Good bracket carb for a 318/340?

You can call Holley on their toll free number and ask them all the particulars. You can actually talk to a real person.

I couldn't find a R6585, but I did find a R80145, which is a 600 vacuum secondary carb. Couldn't find the actual part or application, just lots of parts for it.

Holley carb part numbers.

Kinda small for a bracket race application, or even for the street unless you're after fuel mileage. I've run between 650 and 750 carbs on a 360, usually double pumpers. But a vacuum sec. may be easier to tune. But I suppose it could be decent on a 318. How it's tuned is the important part. A secondary metering block would help with jet changes.

just last weekend i was looking over a Holley like the one described. it had a "Motorcraft" tag with a number very similar to that one...it may be a Ford part #