Race calibrated carb on a mild street car....... Definitely wouldn't be the path I would have taken.

Dwayne is correct, but I wouldn't be afraid of trying that carb. If it isn't easy to sort out then just buy a set of billet metering blocks to solve the problem. The only real issue that you might have with that carb is the idle will be too rich. The old school solution was sticking a wire into the idle jet but now days you can buy a billet metering block with replaceable jets. Or you can drill and tap the old style blocks for replaceable idle jets.

The annular boosters add a bunch of bottom end torque during cold weather so that is good for a street car.

yeah, main reason i wanted to try that carb was because of the annular boosters. thinking this is just a 750DP with annular boosters.

the IFR doesn't seem huge, atleast not like mighty demons have.
i don't have any .030 wire around, but the IFR is smaller than .035 and .023 is moderately loose...maybe it's around .028

but yeah, i will give it a shot and if it's way off maybe put some billet plates on it or maybe send it off to Thumpr...

i guess i'll let you guys know how the idle speed works out with the drilled plates.

on the timing, i will mess with that once i drive it a little. want to make sure it runs ok on pump gas at 36* first, then i'll weld and file the dist plates to get the initial timing right.

Agree about the "as is" calibrations but I modded one for a buddy`s Cobra kit car and he`s never been happier........it replaced a street avenger.............

The drilled plates might give you too much air at idle with a mild cam. You can use a small pop rivet to close off the holes as a tuning trick. Once you figure out if you need the holes or not you can buy a new base plate or have new throttle plates put in your base plate. Or have someone solder the holes up or find another fix.

The new Ultra XP carbs with the idle air adjustment are super slick. No more drilling throttle blades!

thanks andy, i just ordered drill bits and set screws, in case i need to change the IFR...atleast i can figure out the IFR/pvcr and bleed sizes now.

that said, it seems the primary metering block for the 9379 carb i have is the same as the old holley 750DP carbs, 4799-2 and 8156 (late 70's)

the larger 830 and 850 (r9380 and r9381) carbs in the same series as my carb have primary metering blocks #34R8558AS
atleast according to this reference
http://www.lbfun.com/warehouse/tech_info/fuel%20&%20intake/CarbList.pdf

ok, called holley tech line.
also, that holley link i posted above says the metering blocks are different for the 9379 and 9380/9381 carbs, but all the internet searching i've done makes it seem like the 750cfm carbs have the same blocks as the 830/850 carbs.

so this r9379 carb has 8543 3 (primary) and 11038 6 blocks

IAB is .066
HSAB is .030
IFR is .033 (low position)
PVCR is .028 (most stuff i read says 750 carbs are ~.056, so i guess that's .028 x 2 ?

two main well bleeds at .028

anyway, i'll run this thing like this for now. i usually tune by adjusting idle mix with a vacuum gauge, then jet it lean enough that it just barely does a little surging/blubbering at steady cruise then jet back up so that it smooths out.
get the PV sensitive enough that it reacts quick and keeps it from going lean with more throttle input.

at this point i'm not worried about full throttle blasts. that will come with time... this carb has .028/.031 squirters and pink pump cams.

I have one like Dragula

well, got the small drill bits but i think the 80-61 index bits i got are inaccurate so i still don't know what the IFR is.

but the PVCR is NOT .028 like the holley guy said, it's .052
and the IAB .067

the following numbers i got are probably not correct
IFR is .026
HSAB primary side is .025 and secondary side is .021



but, i got my exhaust done. the x pipe makes it sound raspy...
gonna put the lokar stuff and the holley carb on soon

Are you measuring the bits w/callipers? I compared my "good" callipers to Pettis`s great ones and mine were .002 tight so now I add that to my numbers and they exactly match the numbers in the containers the jets come in. I have seen some interesting "as shipped" jets/bleeds in some carbs............good luck.

well, put the carb on the other day and the idle speed can go low enough with the holes drilled in all the plates so i didn't have to put undrilled plates on.

my idle screws were only 3-4 turn out though, i checked with a better set of drill bits and the IFR's in the blocks were .032
i made sure i could drill some set screws i got and it worked out, did .0292 and .028, then i decided to drill and tap the IFR slots.
taped 'em up real good to keep debris in the ports minimal and it seems to be fine.
put the .0292 screws in there...

pulled the intake because i was leaking a little coolant form the front and i'm waiting on new gaskets so i'm not sure where my idle screws will fall now.

Untitled by misomad, on Flickr

You need to lower those a bit more cos they`re blocking the feed holes............

will do, thanks Thumpr!

No prob..............just enuff to uncover the feed passage and you should be good...........

this low enough? i think the pic makes them look higher than they really are.
those are 1/8" screws btw.

Untitled by misomad, on Flickr

Bottom looks more like it...........I set mine flush or just below..........

well, drove the car around a bit with the carb at factory baseline except for the .029 IFR's front and rear.

seems ok, it's a little grumpy while driving until it warms up all the way so that's about right. no bogs after it's warm...
the plugs which were fouled from the edlebrock are cleaning up some. i have some new NGK bk6re to put in place of the non projected heat range 7 plugs in it now.

got on it through a little of first, pulling way harder than it was. surprised me a little actually.

also, i bought some old MP distributors for cheap, both had some runout in the shaft so i went down the rabbit hole of pulling them apart to check out the internals.

now i have the plates welded up on the pro comp dist in the car, should be able to run 18/34 for the timing. left the factory pro comp light spring in and put the really light MP light spring in place of the heavy spring. maybe i'll get timing all in by 2500 now ??
haven't put the timing light on it except to get initial close...

What carb again? .029 ifr`s are not typical from most I`ve seen/worked on do you have a wb?...........

holley 0-9379
think about a 0-4799 750 double pumper with annular boosters
originally it was .032 IFR in the low position, i set it up and the idle screws were only .75 turns out

IAB is .067
HSAB .031/026 prim/sec
squirters are .028/.031
old school metering blocks, i think the well bleeds were .028, two of them
i only drilled and tapped the IFR's

all four throttle plates are drilled to 3/32 so the plates are closed way down, the transfer slots are probably barely peeking through the primary side, secondary side setup to mimic the primary side by holding the up to light then i adjusted both evenly to get idle speed up.

remember this is a pretty mild 360, 190 psi cranking pressure
pulls 13" vacuum at idle in park, 800rpm
magnum heads, headers, xpipe