9.5 MPG!!!! Please Help!!!! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

nosfed2 · 03-23-2013, 10:08 PM

Ok so it is a 1984 Gmc 1500 2wd It has a New 350ci with 1200 miles on it with a RV cam. It also has a 700R4 tranny with 2.73 gears in the rear.It has a stock intake and Quadra jet on it that has been rebuilt by national Carbs, It does not smoke or smell like its running rich. I pulled the plugs and they are perfect. I dont care about towing or anything, we drive it to swap meets that are 30 to 70 miles away one way. We need it to get the best gas mileage possible. The thing is that I watch the tech and at 55mph it is at 1500rpm it never gets over 2000rpm even on a hill so I dont understand how it can be getting such bad mileage. We checked the brakes and wheel bearings for drag but they are all ok. It also has 31X10.50 wheels on it.What is the Deal?

03-23-2013, 10:08 PM	#1
nosfed2 Registered User Join Date: Jul 2012 Location: Chester Il Posts: 32	9.5 MPG!!!! Please Help!!!! Ok so it is a 1984 Gmc 1500 2wd It has a New 350ci with 1200 miles on it with a RV cam. It also has a 700R4 tranny with 2.73 gears in the rear.It has a stock intake and Quadra jet on it that has been rebuilt by national Carbs, It does not smoke or smell like its running rich. I pulled the plugs and they are perfect. I dont care about towing or anything, we drive it to swap meets that are 30 to 70 miles away one way. We need it to get the best gas mileage possible. The thing is that I watch the tech and at 55mph it is at 1500rpm it never gets over 2000rpm even on a hill so I dont understand how it can be getting such bad mileage. We checked the brakes and wheel bearings for drag but they are all ok. It also has 31X10.50 wheels on it.What is the Deal?



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