Author Topic: carb questions  (Read 4757 times)

Offline old blue 75

  • Garage guy
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  • Posts: 24
Re: carb questions
« Reply #30 on: September 10, 2022, 08:53:26 AM »
Hi Cliff I got my kit in the mail(thanks).
I was re reading the book and looking at the carb. I have.
My engine being identical the the example on page 94 LH column,
my idle channel and idle air bleeds are different. Are they far enough
off I need to fix them or will it be ok as is. Also it looks like I should drill
out the mixture screw holes.
In my kit i received new jets and primary rods, same size as stock(71 jet, .040 rod).
With this being a large air bleed carb do i need to go up in jet and rod size?
Looking at example 3 on page 98.
Page 106 it shows drilling the secondary air bleeds to .036.
Is this some thing I should also do?
Not sure how many of these changes I should make and or what to leave stock.
Thanks in advance.

Carb as it sits.

Idle tube .044 (new ones in the kit .036)
Idle down channel .053
Upper idle air bleed .092
lower idle air bleed .063
Idle bypass .097
mixture screw hole .074

Air bleed main body .119
Air bleed air horn .120
main jet .071
primary rod .040 tip .026

secondary air bleed .026
Secondary air flap 1.390
Accelerator discharge holes(poe) .042
Secondary accelerator wells(poe) .034
J hanger CP rods


Engine and vehicle.

Engine 355 sbc flat top pistons (.020 gasket .024 piston to deck.), 441 heads 1.94/1.50 valves bowl blend,  crane hr-260-2-12 hyd. roller cam (lift .429 I .452 E  dur 260 270 dur @.050 204 214 112 lca), stock gm gjet intake (aluminum version egr removed) 1 5/8" headers, hei dist.
 It is in a 1986 short box chevy 4x4, 700r4 trans. crappy 3.08 gears, stock 235/75/15 tires.

Offline Kenth

  • Jet Head
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  • Posts: 434
Re: carb questions
« Reply #31 on: September 10, 2022, 11:48:18 AM »
I suggest installing .050" main air bleed inserts in airhorn and float bowl, use .067"-.068" main jets with yours 40B rods and a set of DA secondary rods.