View Full Version : Holley list 4548-S 450 cfm metering block

01-30-2013, 05:08 PM
I have 2 Holley 9510-U list 4548-S carbs main bodies. I am setting up for street blower (671 on 355 Chevy). I however, have had them apart for a very long time and they have been in a box with 30+ other Holley carbs and parts I do not know what primary metering block or secondary metering plate went on them. Any help with the proper size blocks would help me look through them and hopefully find them again or could try to find new ones... Help please if you can... Johnrodz

01-30-2013, 05:20 PM
My old black book says primary metering block 34R-6343A, secondary plate 34R-2007-30.

01-30-2013, 10:52 PM
hotstuff, I can't find anything in my box with those numbers. I looked at Holley's list of blocks and plates and found nothing there. Are their other possible blocks and plates for 450 Holleys that could be used? I did find out that they had .057 main jets...but no other tech info as to plates, blocks, etc. I'm thinking that carbs found on ford 2x4 setups in the 60/70s that were 450 cfm that the blocks and plates may be what I need...any ideas???? Thanks, johnrodz

01-30-2013, 11:37 PM
If I knew what the sec plate jet hole size and the idle bleed size are I could buy a 34R9716-3 plate (Holley's smallest plate listed) and redrill it to the 34R2007-30 plate specs and I could get a block with adjustable bleeds and speck it to the 34R6343A block. You got any idea what the specs are for the block and plate you found in your black book?

01-31-2013, 12:17 PM
R-4548AAA model no. 4160C, TV Ill24-2, Ford service, 320, 390, 428 & 429 Eng. auto trans. vehicle part No. D0PF-9510-U Service replacement No. 1-191 renew or master kit 3-119. I couldn't find a CFM on this carb. I have an old book with old numbers. I would try using the Ford number for information. The plate stamped 30 main restriction Hole A .064, idle Hole B .029

01-31-2013, 01:22 PM
Most 4160C are 600 CFM, Holley recommended the 4845 for Ford full size 289, 302, 351 cu.in. for 1966-69 street use. Most guys are using the R-8007, 390 CFM depends on your need, but there are other 450 CFM carbs in 1975-77 marine 302 for example.

01-31-2013, 04:46 PM
OK it is a 450 CFM needle & seat 6-506, Pri jet 57 pump nozzle .031, sec. spring brown, I used to run a 355 with a 671 huffer strip mainly I think your 450s will work fine.

01-31-2013, 04:54 PM
Found that 450 CFM Holley marine carb R-6407

01-31-2013, 04:57 PM
OK, now we are gittin somers. Those carbs I have are Holley 9510 U list 4548S. I did find a #30 plate in my box of parts and also found a metering block with 57 jets. The # stamped on the block is 8221 and a second # stamped on it 8222 with a #3 stamped under that #. I think this is what came on the carb. If this is right, I will need another block and plate for the second carb, as I do not have a match for the ones I found. Can you tell if these may be the correct ones? By the way these are square bore carbs. I have found many (spread bore) 450s in the Holley listings but no listing for the 9510U list 4548S. Thanks guys, I think I'm a gittin somers now. John

01-31-2013, 05:05 PM
Think the plate is right, but the block you have to check with the Holley Techs.

01-31-2013, 05:26 PM
Yea Troy, I'm thinking the samething. Just not sure enough to try that block just yet. I have tried to get through to Holley's tech line but the wait has been long and I just give up. Just have to keep trying...your help has been great. Thank You ever so much...John

06-11-2013, 12:01 AM
Hi johnrodz. Not sure if you still need help, but if you do, the correct numbers on the Holley 4548-S primary metering block are 6343 and below that number is 4548. Some don't have the 4548 on them below the 6343, but most that I have seen do. The secondary metering plate is #30 and below that is 34R-2007 B. Rick