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Curious, Highway RPM question on old Chevy 4X4 - updated with pictures! :)

Discussion in 'The Garage' started by Ancient4X4, Apr 12, 2007.

  1. Ancient4X4

    Ancient4X4 Registered Member

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    I have an old Chevy truck, 4X4, NP203 (full time 4X4) and I was wondering what type of RPM's I'm doing at 70mph on the interstate.

    It's a 1977 Bonanza with a 400ci and TH400 tranny. The carb is an Edelbrock with either 600 or 650cfm and I think it is a Q-jet and has the performer intake. It has 3.08's and stock sized Dunlop tires, about the normal size it would have come with from the factory.

    I've had the needle buried way past 100mph. If I had to guess, it probably tops out around 115-120mph. It can really move with that 175HP 400ci V8. I'm assuming my best possible gas mileage is at 50mph with the 3 speed tranny, but I'm curious what type of RPM's I'm running at Interstate speeds.

    The truck is basically original, aside from the electronic choke edelbrock carb and intake manifold, both put on back in 1992. Vehicle has just over 95,000 miles now. Any other info needed let me know. There's no RPM gauge in the dash.
     
    Last edited: May 2, 2007
  2. b454rat

    b454rat 1/2 ton status Premium Member

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    The 3.08s will help out alot on the highway. Guessing stock size tires are 235/75/15, about 2500. If it has 31s, drops down to around 2300.
     
  3. obijuan

    obijuan 1/2 ton status GMOTM Winner

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    PICS PICS PICS!!! i had a 77 bonanza 2wd truck, i have never seen another. PICS!
     
  4. divorced

    divorced 3/4 ton status

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  5. Ancient4X4

    Ancient4X4 Registered Member

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    Hey, thanks for the info guys! I read about people not liking to run their engines over 3,000 rpms for extended periods of time so I was kinda wondering. I usually drive at 60mph even in the 75mph zones to save gas if I'm not in a hurry to get somewhere.

    obijuan, I'll take a couple pictures either tonight after work or tomorrow for ya. :)
     
  6. rjfguitar

    rjfguitar 3/4 ton status GMOTM Winner

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    I run my 26 year old original 454 at 3250rpm+ and doesn't bother me..... I've got places to get to.:haha:
     
  7. CutlassKid85

    CutlassKid85 Registered Member

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    thats about the same rpm I cruise my k5's 350 at on the highway
     
  8. dhcomp

    dhcomp 3/4 ton status Premium Member

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    friend of mine did that with his 80s burb, til he threw a rod out the side of the block
     
  9. rjfguitar

    rjfguitar 3/4 ton status GMOTM Winner

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    Well, it was probably time to stick his head in there and do some general maintenance anyway....:rotfl:
     
  10. dhcomp

    dhcomp 3/4 ton status Premium Member

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    yah, for sure. Now that i think of it, i wanna say it was a 78 or somethign, and he was trying to keep up with a 2000 civic coming up i5 :haha:

    no $hit it blew up.....:doah:
     
  11. OffRoad

    OffRoad 1/2 ton status

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    i love this place. guy shoots a rod out the side of his motor, and it's no big thing. lol:D
     
  12. Ancient4X4

    Ancient4X4 Registered Member

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    Sorry, been busy lately but finally got some pics for ya, actually took these a couple weeks ago, haven't gotten around to posting them until now. I'll post some comments above each picture. My truck turned 30 in March! Hard to believe. Here's a picture from the front side.

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    Picture of the backend. The original Cordova Brown paint helps to hide the rust.

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    Back tire. When my dad bought the truck he told them to take the POS hubcaps off and put the Blazer stuff from the truck next to it on the tire. Still there, though somebody stole all four original beauty rings around 1990, those are replacements. My dad said they were trying to get the Blazer stuff off, but something must of scared them because they didn't finish, I'm glad.. I don't think these beauty rings are as nice as the originals though, but I could be wrong. I think the originals were chromed steel and these replacements I got are chromed aluminum, but they look pretty decent.

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    Here's the front tires, yummy grease.

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    Here's a picture under the hood. I'm not a mechanic, but I guess it's a picture of alternator, some hoses, the front of the brake fluid holder thingy I forget the name (I told you I'm not a mechanic :) ) and um.. the air filter on top and carburator spring I guess.

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    Battery and tire jack, coolant cap on the right bottom edge.

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    Poor girl has been bleeding to death for 20 years, but I guess she's used to it by now.

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    I checked the oil after taking these pictures and it was a little over 2 quarts low, but you'd never know it from the oil pressure. One thing about this truck, the oil pressure has always been good, even when there was barely any oil in it. It's like the polar opposite of a Phord. I added a quart, no sense in putting more in, it just blows it out right away.

    Sort of in the upper middle of the picture you can see the shiny fuel filter and new hoses I put that in all by my dumb self about a year and a half ago (I'm so proud of me) it was about $14 worth of parts from NAPA. I think it was worth it since duct tape on the rotten hoses wasn't keeping fuel from spurting all over anymore ;)

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    Little bit of a wider picture, you can see the air condition compressor or R2 unit or freon thingy whatever you wanna call it. I like the horn. It's an old 6V horn from a Model A my dad scrounged from a junkyard many years ago. Hooked up to a 12V battery it's quite loud! I rarely use it because it scares the **** out of people when I do. A few years ago I honked at a guy who decided to take a nap when the stoplight turned green and he just about jumped through the roof of his car.

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    Last under hood pic, nothing special here except I guess you can see I use Quakerstate. This truck never liked Pennzoil in its entire life for some reason and I'm not gonna argue with it. Always liked Mobil or QS.

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    Here's some pictures of the gauges. I have the dash apart because I'm trying to get a new radio since the old one broke. As you can see the oil pressure is good, even on less than 3 quarts of oil. This pic was taken before I added a quart, but while the engine was still cold, usually settles around the middle when it warms up.

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    Another picture of the gauges.

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    And last picture of the gauges. Can't think of any interesting comments to make on them other than they look alot cooler than later gauges. 1977 was the coolest truck ever made! :)

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    Last picture is an interior shot. The glovebox fell out one day when I opened it back in February when I started it to drive to work when it was about -42 air temperature outside (not windchill, but actual air temp) anyways, I'm not sure how I'm going to fix that. I was just so glad it started without being plugged in sitting on the street that I didn't care. I just heard a snap and out it fell. I think there was some cable behind it that I'll have to look for. The gas tank selector is visible in the top of the picture and the transfer case shifter on the bottom.

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    Last edited: May 2, 2007
  13. Ancient4X4

    Ancient4X4 Registered Member

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    Here's a pic of the bed where my bike and spare tire resides. :D

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