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07-21-2010, 09:42 AM
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#1 |
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Registered User
Join Date: Jun 2009
Location: Forest City IA
Posts: 56
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B model or Monojet?
Hi,
My wife's truck is an early 67 C20 with 250 and 4 speed. The manual chock carb is currently a B model Rochester. The carb may have been swapped when the glass pack exhaust was added. It has a larger jet than came stock on a 250. Can I/should I swap to a monojet? The B model is rather worn and will need a shaft bushing to make it work properly and if a monojet is the correct carb I would be tempted to switch over to it. Thanks, Scott |
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07-24-2010, 02:28 AM
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#2 |
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Senior Member
 Join Date: Jul 2008
Location: Central Coast, CA
Posts: 277
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Re: B model or Monojet?
I can't speak about the differences between 1-barrels, but I can tell you that putting a 2-barrel Rochester on my 292 really woke up the engine! Might be something to think about for your 250. my 2¢
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07-25-2010, 11:36 PM
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#3 |
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its all about the +6 inches
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,690
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Re: B model or Monojet?
moved to the truck page... was found on the burb one.
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07-26-2010, 09:27 AM
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#4 |
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Active Member
Join Date: Jul 2007
Location: Centrally located between Houston, Austin and Waco. BCS area.
Posts: 7,947
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Re: B model or Monojet?
Monojets are Rochester/GM carbs. Your B model is an earlier version that was used on some earlier year vehicles. My 68 with 250 has a monojet.
http://www.walkerproducts.com/_pdf/rochester1barrel.pdf http://www.walkerproducts.com/_pdf/C...tion_Guide.pdf |
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07-26-2010, 10:30 AM
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#5 |
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Junior Member
Join Date: Dec 2006
Location: Southeast Missouri
Posts: 2,436
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Re: B model or Monojet?
The 250 in my '67 had the original carb replaced by a MonoJet and it works ok. I still have the old carb I may rebuild some day just for the heck of it. The original carb has a manual choke and the MonoJet has an automatic choke.
__________________
'67 Chevy C-20 short stepper - build complete, 454/SM-465. '75 C-30 Single Cab DRW-350 small block/NP-435. '77 GMC-6500 Dump Truck, 427 Tall Deck. '92 GMC K-3500 Duallie, 454/4L80E. |
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07-26-2010, 04:32 PM
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#6 |
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Registered User
Join Date: Oct 2005
Location: Overland Park, Ks.
Posts: 5,229
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Re: B model or Monojet?
The 67 originally came with a model B. The Monojet came out in 68. The mono. is a better carb but the model B is easier to work on.
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07-26-2010, 08:29 PM
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#7 |
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Who's got steelies?
Join Date: Feb 2006
Location: Morrison, Oklahoma
Posts: 1,025
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Re: B model or Monojet?
I agree with wrenchbender. The Monojet is basically a single primary bore out of the Q-jet, with its triple-venturi cluster.
__________________
 1969 C10 LWB W/ 250 I6 & 3spd1970 C10 with '67 small window cab, 68 front end, blue; 305/TH350, 3.08 limited slip rear end, manual brakes, power steering; & 4-wheel drums-My daily driver.1975 Chevelle Malibu Classic Coupe 350/th350 mint green1970 C20 Suburban 350/700R4 4.10 gearing green & white 1978 Big 10 Silverado 350/th350, working ac, 2 tone blue-My summer daily driver 1983 GMC 1500 Sierra 305/SM465 2.73 rear end How to add a trip odometer to your 67-72 stock speedometer How to rebuild your Q-Jet My Truck Page My Youtube Channel |
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