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73-87 Chevy _ GMC Trucks => Performance => Topic started by: 7Stepside8 on July 04, 2012, 09:21:26 pm

Title: Truck turns 2000 RPM at 50mph w/350TH
Post by: 7Stepside8 on July 04, 2012, 09:21:26 pm
I have no idea about the gear ratio but does this sound normal for stock? It turns about 2500 at 60-65 range as well and truck seems its burning up gas pretty quick for Highway miles.
Title: Re: Truck turns 2000 RPM at 50mph w/350TH
Post by: 454Man on July 05, 2012, 09:00:03 am
I turn the same rpms, same trans and my gears are 3:23 its what came from the factory with a 700r4. In a week the three speed will come out and be replaced with the 700r4. My gas is way down hill worse than a 454.
Title: Re: Truck turns 2000 RPM at 50mph w/350TH
Post by: slammed79 on July 05, 2012, 09:14:27 am
I spin 3k at 70mph and pull about 16-17 on the freeway. 25+ year old trucks aren't known for great gas milage.
Title: Re: Truck turns 2000 RPM at 50mph w/350TH
Post by: 78 Chevyrado on July 09, 2012, 09:16:24 pm
That sounds normal.

My truck turns 2900rpm at approx 70  with a 3.73 rear and 33.5" tires. 

Title: Re: Truck turns 2000 RPM at 50mph w/350TH
Post by: Jason S on July 09, 2012, 09:27:04 pm
Doesn't sound bad.  My '73 K2500 runs about 3000 rpm at 70 mph with 4:10 rear and TH350.  My 2005 2500HD 4x4 runs 2000 rpm at about 60 with 4:10 rear in 5th gear.
Title: Re: Truck turns 2000 RPM at 50mph w/350TH
Post by: choptop on July 11, 2012, 09:57:41 pm
I was talking to a friend of mine the other day about how high revving these trucks are compared to the newer ones. Anyone else realize that when these trucks were new, the speed limit was 55mph? The best fuel economy I have gotten out of any of my trucks was 55-60 mph..Coincidence??? I think not.
Title: Re: Truck turns 2000 RPM at 50mph w/350TH
Post by: 454Man on July 11, 2012, 10:39:50 pm
True
Title: Re: Truck turns 2000 RPM at 50mph w/350TH
Post by: codyC10kid on July 29, 2012, 11:01:16 am
i was just go
I was talking to a friend of mine the other day about how high revving these trucks are compared to the newer ones. Anyone else realize that when these trucks were new, the speed limit was 55mph? The best fuel economy I have gotten out of any of my trucks was 55-60 mph..Coincidence??? I think not.
I was just going to say that....thats why i go 55-60
Title: Re: Truck turns 2000 RPM at 50mph w/350TH
Post by: Stewart G Griffin on August 26, 2012, 08:39:46 am
When you are turning 2500rpm, what is the throttle position?
Title: Re: Truck turns 2000 RPM at 50mph w/350TH
Post by: codyC10kid on September 03, 2012, 02:48:43 pm
My new motor i built 95 K1500 350 bored to 355 compression ratio 10.2:1 comp cams extreem 4x4 cam 262 cam roller tip rockers edelbrock EPS intake 600 rm performance. cali. carb 203 transfercase Full time 4x4 33's mud tires 2000 rpm 55ish 3000 rpm 90mph,and drove it 100 miles 65-80mph and got 10.2 MPG....also has a 3 inch body lift and 3/4 ton susp....1977 K10