Thread: Holly 4150 on a Vortec 350 Question

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Holly 4150
Picked it up for $20.00 today at a Garage sale
The owner told me it was Re-Jetted for his Big block chevelle
What jets would be a good starting point for my car??? I've heard (but can't find) of databases that can get you close to the proper jet sizes.
99 vortec 350 w/ GM Hotcam & headers
Any help would be nice... I'd rather not waste hours Re-Jetting when I know someone has the Info I need
John

4150's had different cfm sizes. Got a list number? On the airhorn.

4777-5 650 Cfm

Originally Posted by DennyW

Are you sure that is a 4777-5 ?

4150
4777-5
650 cfm

4150
4777-4

front=67, rear=73
power valve=6.5

That is correct for a 4777-5 carb..... But is that the correct carb part # for a Vortec 350????

Denny is probably right, but I think 67's in the primary might be a bit too stout. I ran a 650 DP on a 400sbc with a fairly healthy cam and ended up with 65's in the primary to keep it from running too rich. What size of pump shooter does it have in the primary and what size accelerator pump housing in the primary?

Originally Posted by DennyW

4150
4777-5
650 cfm
4150
4777-4

front=67, rear=73 or 76
power valve=6.5

R4777-5=part number
4150=carb model
650=cfm
37-485=renew kit
37-933=trick kit
6-504=needle and seat
122-67=primary main jet
122-73=secondary main jet
34R8539-5AMP=primary metering block
34R6497-3AMP=secondary metering block
125-65=power valve
0.028=pump nozzle size primary

That's what came in the 4777-5 carb
This carb has been Jetted for a BB chevy so I'm sure it's all wrong!
I've not tore it down yet so I don't know what's in it now but I'm sure it's all wrong ( being set up for a BB) and I'm just looking for a good starting place For my vortec 350

Talk about lucky!!!
I Called Holley and asked them what carb would be for my set-up and..... It's the correct carb # for my car/Engine

So I'm going to get the re-new kit from Holley and have a nice little INDOOR project for these HOT summer nights putting the stock Jets in my carb & going through it.