engine rpm question

Got a 1990 Chev 4x4 truck with 350, 700r4 tranny and stock size tires. My question is what should my truck be revving at driving 60mph? I threw in a tach and it is revving at 2600 rpm @ 60. Some say that's too high, your
tranny must be slipping. Not sure on what gears I'm running but I'm sure they are 3.47s or something like that.
Alex
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Not sure about the 350 but I do believe thats what I run at 60 with my 4.3. But I am standard tranny and I rarely run 5th gear anymore because she doesn't like it. How many miles do yo have on your truck?

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1,900 to 2,200 I would say is the average.
2,600 is totally ridiculous. 4.10 gears and a three speed would probably run slower. check that tach again.
HDS
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I run about 2200-2400 with 3:73 rear. Factory tach. We all know how stupendously accurate those are.
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To run 2,600 @ 60 mph with 3.42 gears you would need 24" tires.... http://www.drivetrainsuperstores.com/gear_ratio_chart.asp click the link, know your tire size and read the chart, you want to be in the pink area of the graph.
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A little high in my opinion. Is your torque converter locking up??? When driving down the road lightly press on the brake when you have you other foot on the gas. You should feel the converter unlock and the rpm will kick up ~500rpms. I have a 4.10 rear on truck tires (stock to the 3/4 ton burban) and run about 2100-2200 at 60mph. I bet your converter is not locking up. You probably have a 3.21 or 3.73 rear if you look at the options sticker (glove box or some place similar it should tell you) or you can take you vin into your local friendly dealer and they can tell you.
good luck, mark
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I`m almost positive you have either 3.42 or 3.73 gears. Are you running in drive,or overdrive?
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Did you remember to set the tach for V-8 application?
********************
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"Brian Orion" wrote: > Did you remember to set the tach for V-8 application? > > ********************
I have a 97 GMC sierra and I run about 1700-1800 RPM at 60 MPH. I have stck everythin so I would say you are running a bit hihg. could be an issue with the truck but I would say it is in the tach myself!!
nickl
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That is to high if yor running in od. What brand of tach are you using?
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When I hooked a scope to the truck and revved up the engine, the tach showed 2600 and the scope showed 2000. The tach needle also jumps around abit. I put the tach in different vehicle and it operated perfectly. Do I maybe have a coil problem in my truck? There is a slight miss in the engine when it idles.
Alex

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As I asked before,what kind of tach were you using? Some tachs don`t work right with all vehicles.
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