gmbellew
Full Access Member
- Joined
- May 27, 2018
- Posts
- 1,211
- Reaction score
- 1,277
- Location
- Kansas city
- First Name
- glen
- Truck Year
- 1990
- Truck Model
- suburban 1500
- Engine Size
- 350
also verify speedo is correct with your phone GPS
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I’m not 100% sure but that’s what the build sheet says and it looks stock. Last night I was driving and it did go into third gear.My question is why do you think you have 3.73 gears? it Sounds more like 4.56s or your only getting first and 2nd gear.
Whenever I go through town and drive by a speed check thing it looks accurate. But I will try the phone onealso verify speedo is correct with your phone GPS
It’s an aftermarket tach, I’m in McMinnville oregonHow do you know what your RPM is? Factory tach? Aftermarket one? Where are you at in Oregon?
It’s an aftermarket tach, I’m in McMinnville oregon
The tach is up by around 220 rpm according to my timing lightHow do you know what your RPM is? Factory tach? Aftermarket one? Where are you at in Oregon?
She’s not quite screaming but she’s definitely up there in the rpm according to my ears lolgood question about the tach. I am not that familiar with aftermarket tachometers or if there are different types, etc.. but at 3500 rpm the engine should definitely be making some noise. that can be used as a quick reality check on the tach readout. is the engine really screaming at 55mph?
Okay I just drove it on a backroad, she is shifting into third gear. The tach was saying 3,400 rpm at 55 however it is up by around 220 rpm. The speedometer is pretty spot on. So given that info the rpm’s at 55 are close to 3,180.She’s not quite screaming but she’s definitely up there in the rpm according to my ears lol
By a timing lightI'm gonna venture to guess either you have way more gear than 3.73 (either the original axle has been regeared or it's been swapped with another axle) or your tach is off more than 220rpms. How did you verify it was off by 220?
The timing light has a tach on itBy a timing light
Oddly enough this tach (which I bought on Amazon) advertises it works on 4-6-8 cylinders engines however it doesn’t have any switch to change between themI remember some aftermarket tachs having a small 4-6-8 switch for the number of cylinders on the engine….