What should the stamped (casting) # be on the primary block? The one on mine - used carb - is a 4033. Carb in question is a 4780 (no -suffix) double pumper.
I suspect it's the wrong primary block due to an idle issue that I don't have when I swap my 750 onto the motor.
Tried the search function, my Holley book (only says "not serviced"), Allstate Carb, Google, no luck; but I'm sure I've seen the info somewhere.
Thanks in advance.

I was curious and Google'd "Holley metering block 4033"; what came back seemed to point to that # being something found on old FE Ford 2-4bbl applications, but that's just from a quick glance at the list of links returned.

I wonder if a basic 850 DP primary block would work on an 800, since they share the same venturi size, even though the 800 uses the smaller 1-11/16" baseplate?

Look on here
https://www.holley.com/data/TechService/Technical/Carb%20Numerical%20Listing.pdf

I think that's what the OP looked at when he stated "...Holley book (only says "not serviced")...".

See if you can find something here. Proform also makes several
http://www.summitracing.com/search/brand...cks-replacement

Yup, that's the problem: 750 or 850 metering blocks, no 800, which I assume by exclusion aren't right for the 800. Appreciate y'all looking into it. Previously I found the # for the Secondary block, but I don't remember where, dang it.

There used to be another holly site that I really liked. I found a number for someone 2 weeks ago and when I went to it this week its gone. I can't tell you how many times I used that site. I will dig into it after a good shower and see if I can relocate it.

Thanks; there used to be one called "mortech" or something similar, but they have no metering block info, only jets & PV.

For the 4780 and the -1 and -2 they show N/S but for
the 4780-3 they show 34R11196AQ as the primary plate...
I would need to look up the main body numbers to see
if the main body is different... if it isnt then the
-3 shown should work(it shows the same pri plate
for the -3 through -7)

At loking at the main body it looks like the -4 will
work... the first in the numbers is the 4780 and the
last line is the 4780 -4... the -3 had some minor change
with a suffix change but the -4 is the same as the -2
N/S 1-3/8 1-7/16 1-11/16 1-11/16
0.031 108-83-2 108-89-2 108-83-2 108-89-2 N/R 134-103 134-104 12R11090AP 1-3/8 1-7/16 1-11/16 1-11/16
0.031 108-83-2 108-89-2 108-83-2 108-89-2 N/R 134-103 134-104 12R11090A 1-3/8 1-7/16 1-11/16 1-11/16
0.031 108-83-2 108-89-2 108-83-2 108-89-2 N/R 134-103 134-104 12R11090A 1-3/8 1-7/16 1-11/16 1-11/16
0.031 108-83-2 108-89-2 108-83-2 108-89-2 N/R 134-103S 134-104S 12R11090A 12R11090A
EDIT
It looks like this should work 34R11196AQ

Thanks, soon as I can find what # it is I'll bother you. I don't expect it to be free, though.
I'd like to get the exact # it's supposed to have so I can stop chasing my tail on this carb.
Funny thing is, my 750DP runs perfectly on the car, but the baseplate linkage won't allow me to connect the throttle cable. I'd rather have 2 good carbs than cannibalize one for the other; otherwise this thing would be at the muffler shop already.

Aftermarket Detailed Holley Carburetor Info
Enter Holley Part No
Part No Model CFM Renew Kit Trick Kit Needle And Seat Primary Jet Sec Jet or Plate Pri Metering Block Sec Metering Block Pri Power Valve Pri Nozzle Sec Nozzle or spring color Pri Bowl Gasket Pri Metering Block Gasket Sec Bowl Gasket Sec Metering Block Gasket Sec Metering Plate Gasket Primary Fuel Bowl Secondary Fuel Bowl Base Plate Pri Venturi Diameter Sec Venturi Diameter Pri throttle Bore Sec Throttle Bore Notes
0-4780 4150 800 37-485 37-933 6-504 122-72 122-76 N/S N/S "(12,21)" 0.031 0.031 108-83-2 108-89-2 108-83-2 108-89-2 N/R 134-103 134-104 N/S 1-3/8 1-7/16 1-11/16 1-11/16
0-4780-1 4150 800 37-485 37-933 6-504 122-70 122-76 N/S N/S "(12,21)" 0.031 0.031 108-83-2 108-89-2 108-83-2 108-89-2 N/R 134-103 134-104 N/S 1-3/8 1-7/16 1-11/16 1-11/16
0-4780-2 4150 800 37-485 37-933 6-504 122-70 122-85 N/S N/S 125-65 0.031 0.031 108-83-2 108-89-2 108-83-2 108-89-2 N/R 134-103 134-104 12R11090AP 1-3/8 1-7/16 1-11/16 1-11/16
0-4780-3 4150 800 37-485 37-933 6-504 122-71 122-85 34R11196AQ N/S 125-65 0.031 0.031 108-83-2 108-89-2 108-83-2 108-89-2 N/R 134-103 134-104 12R11090A 1-3/8 1-7/16 1-11/16 1-11/16
0-4780-4 4150 800 37-485 37-933 6-504 122-71 122-85 34R11196AQ N/S 125-65 0.031 0.031 108-83-2 108-89-2 108-83-2 108-89-2 N/R 134-103 134-104 12R11090A 1-3/8 1-7/16 1-11/16 1-11/16
0-4780-5 4150 800 37-485 37-933 6-504 122-71 122-85 34R11196APQ 34R11198APQ 125-65 0.031 0.031 108-83-2 108-89-2 108-83-2 108-89-2 N/R 134-103S 134-104S 12R11090AP 1-3/8 1-7/16 1-11/16 1-11/16
0-84780 4150 800 37-485 37-933 6-504 122-71 122-85 34R11196A N/S 125-65 0.031 0.031 108-83-2 108-89-2 108-8

http://www.carburetion.com/HolleyNumbers.asp

Find my post that has an attachment.
https://board.moparts.org/ubbthreads/show...rue#Post5478703

Thanks, I see there's no casting # info or new part; guess I gotta find someone with a complete old 4780, get the casting/stamped #, and look for a good used block.
Leigh, went through that old post, have that book, same info or in this case, lack thereof.

I think I have a set of metering blocks from an old 4780 I converted to billet blocks to tune on . Ill let you know tomorrow
Keith

Did you open up the word document attachment? It contains the stamping numbers in my collection.

Yeah, Leigh, I did; for what it's worth, my Sec block is a #6514, and is also stamped "4780" in a smaller font.

Alrighty then. Looks like we need to see what numbers are on Dannucks 4780. Mine was a 4780-2.