Bought a carb at a yard sale. Help identifying? (pics added )

[FoFittyFoSS]

Like the title says. It is a Holley double pumper. Written on the side in permanent marker "ARCA spare #2". The letters MWR are engraved by hand on the top and the name BLAKE was hand stamped next to that. The Holley casting # on the top are 3390. Cast on the base plate are the #12R-4507-BR and another number on the base plate is 48354.
There is no choke or tower and never appears to have had one. There are two power valves in this thing as well. It is dissasembled and soaking in a bucket of carb cleaner right now. Anybody know what this thing is. I have no idea any age or history nor did the previous owner. Thanks.

[squirrel]

Re: Bought a carb at a yard sale. Help identifying?

number on the air horn is what we want, without we're gonna need pictures

[milner351]

Re: Bought a carb at a yard sale. Help identifying?

doesn't sound like it's ever had a primary air horn so - list number ID is out the window.

Front and rear power valves help the ID - but pictures would be best.

One thing for sure - this aint a run of the mill 600 vac!

[Scott Liggett]

Re: Bought a carb at a yard sale. Help identifying?

Throttle blades diameter measurement and inside diameter of venturis, plus throttle bore diameter.

Also, does it have four corner idle, dual accel pumps, two power valves?

[FoFittyFoSS]

Re: Bought a carb at a yard sale. Help identifying?

Four corner idle, dual power valves, never had an airhorn, double pumper so yes two acc. pumps. I cant take pics as it is soaking and apart. Maybe tommorow. Have a 750 4150 and this thing looks bigger. I'll get a measurement of the openings. Mechanical secondaries.

[SpiderGearsMan]

Re: Bought a carb at a yard sale. Help identifying?

didn't arca use a 390 cfm ? I know busch cars did at one point

[fabricatordave]

Re: Bought a carb at a yard sale. Help identifying?

michael waltrip racing--------MWR ????????????????/

[squirrel]

Re: Bought a carb at a yard sale. Help identifying?

Morale, Welfare, and Recreation.

(that's what the MWR sign on Ft Huachuca means)

[IRONHEAD]

Re: Bought a carb at a yard sale. Help identifying?

sounds like a worked 390
but need pic's

[FoFittyFoSS]

Re: Bought a carb at a yard sale. Help identifying?

Throttle bore Dia. = 1.6575", Throttle blade Dia = 1.7175". Best I could measure till it's cleaned up. Looks pretty big to be a 390 but hopefully someone here can help me figure this out. I'll piece it back together for pics after work.

[squirrel]

Re: Bought a carb at a yard sale. Help identifying?

750? 830? 8004?

[IRONHEAD]

Re: Bought a carb at a yard sale. Help identifying?

michael waltrip racing--------MWR ????????????????/

or mark wlliams

[Scott Liggett]

Re: Bought a carb at a yard sale. Help identifying?

Throttle bore Dia. = 1.6575", Throttle blade Dia = 1.7175". Best I could measure till it's cleaned up. Looks pretty big to be a 390 but hopefully someone here can help me figure this out. I'll piece it back together for pics after work.

Assuming my conversion to fractions of an inch is correct; 1 11/16 is common to 650 to 800. Four corner idle and double pv's started with 800's. I need venturi bore size, that's around the the booster, to be sure of it's size. A 750 will be 1 3/8 front and rear, an 800 will be 1 3/8 front and 1 7/16 rear.

It's not an 850 or bigger as the throttle bore on those is 1 3/4 inch front and rear.


The throttle bore and venturi bore tells the real story of it's size. This is because people modify carbs heavily over the years, like using two primary metering blocks. That's easy to tell if there is a vacuum port on both metering blocks. If just one has a vacuum port, but both have pv's, it's gets you closer to the answer.

[nosnerd]

Re: Bought a carb at a yard sale. Help identifying?

Throttle bore Dia. = 1.6575", Throttle blade Dia = 1.7175". Best I could measure till it's cleaned up. Looks pretty big to be a 390 but hopefully someone here can help me figure this out. I'll piece it back together for pics after work.

Assuming my conversion to fractions of an inch is correct; 1 11/16 is common to 650 to 800. Four corner idle and double pv's started with 800's. I need venturi bore size, that's around the the booster, to be sure of it's size. A 750 will be 1 3/8 front and rear, an 800 will be 1 3/8 front and 1 7/16 rear.

It's not an 850 or bigger as the throttle bore on those is 1 3/4 inch front and rear.


The throttle bore and venturi bore tells the real story of it's size. This is because people modify carbs heavily over the years, like using two primary metering blocks. That's easy to tell if there is a vacuum port on both metering blocks. If just one has a vacuum port, but both have pv's, it's gets you closer to the answer.

rebel is on the right track here...looks to me as a 830...BLAKE is big in the roundy round classes.call them 704-663-7628

[FoFittyFoSS]

Re: Bought a carb at a yard sale. Help identifying? (pics added)

Great info Rebeldryver. Cleaned the carb up and put a kit in it tonight. I found epoxy used extensively on this thing. The pin that holds the platic vents in the bowls and the boosters were epoxied in place. Epoxy in the throttle openings to reshape or make the holes smaller. You will see in the pics the two cavities in the top of the carb appear to have the same epoxy in them. Still a little on there I need to get off. Idle mixture screws had the gaskets but were still filled with silicone. Anyway, I hope these help.