What Final gear ratio? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Lowerd1 · 09-26-2003, 09:04 PM

I am trying to figure out what the final gear ratio is of my 1978 Chevy Silverado. Can anybody help? I looked on the Rear end thinking it may be there but its not. Is there a place on the truck where its located or a way of finding out?

1978 Chevrolet Silverado
350 4bl
TH350
12bolt rear end

**N2TRUX** · 09-26-2003, 09:35 PM

Did you check the glove box? My 77 still has the build tag in there. It shows all the options (or lack of) on my truck, including the gear ratio...

Lowerd1 · 09-26-2003, 10:00 PM

I checked the Glove box and found the Options sheet but it doesn't say what the Rear end is.

gldevall · 09-26-2003, 10:06 PM

If you have a tach, check your RPM's at 60 MPH and work backwords through a gear calculator

**N2TRUX** · 09-26-2003, 10:12 PM

Does it have the original seat in it? There is sometimes a build sheet slipped in the springs under the seat. It may have it on there.

According to the experts, it is on your rear end, but is hard to see. I have never verified mine, so I can't tell you where it's at exactly. If I remember correctly, it is stamped on the back side of the axle tube close to the pumpkin, and (maybe) on the right side...

Lowerd1 · 09-26-2003, 10:33 PM

No Tach. I will check the Seat tomorrow.

As for the Rear end I looked all over and I could not find it. I will look tomorrow again though.

Cole's 87 · 09-27-2003, 04:59 AM

Well if its time to change the oil in the rear end just count the teeth and divide the ring by the pinion gear

ex: 37 teeth on ring
12 teeth on pinion
=3.08 ratio

**swervin ervin** · 09-27-2003, 05:50 AM

You will have to clean everything real good to see it, but if you look on the passenger side axle tube, on the front side, about 4 to 6 inches out from the center section, there is a stamped code. It's small, about 1/8" or so in size. It's very hard to see sometimes as it was die punched and not cast into it.

Anyway, if you can find this code, let me know what it is and I can tell you what it came with from the factory.

**N2TRUX** · 09-27-2003, 07:37 AM

Quote:

Originally posted by swervin ervin
You will have to clean everything real good to see it, but if you look on the passenger side axle tube, on the front side, about 4 to 6 inches out from the center section, there is a stamped code. It's small, about 1/8" or so in size. It's very hard to see sometimes as it was die punched and not cast into it.

Anyway, if you can find this code, let me know what it is and I can tell you what it came with from the factory.

That's what I was trying to remember! I knew Mike and Chris had posted this before.

I was pretty close, except it's on the "front" side, not the back. Thanks for bailing my failing memory out Mike...

09-26-2003, 09:04 PM	#1
Lowerd1 Full Time Loser! Join Date: Feb 2003 Location: Murfreesboro Tennessee Posts: 65	What Final gear ratio? I am trying to figure out what the final gear ratio is of my 1978 Chevy Silverado. Can anybody help? I looked on the Rear end thinking it may be there but its not. Is there a place on the truck where its located or a way of finding out? 1978 Chevrolet Silverado 350 4bl TH350 12bolt rear end __________________ 1979 C10 - Its being rebuilt. 1978 Silverado - Its being driven. 1995 Grand Prix GTP - Its stock

09-26-2003, 09:35 PM	#2
N2TRUX Happy to be here Join Date: Mar 2000 Location: Cypress, TX Posts: 39,021	Did you check the glove box? My 77 still has the build tag in there. It shows all the options (or lack of) on my truck, including the gear ratio... __________________ Follow me on Facebook and Instagram @N2trux.com Articles- "Jake" the 84 to 74 crewcab "Elwood" the77_Remix 85 GMC Sierra "Scarlett" "Refining Sierra"

09-26-2003, 10:00 PM	#3
Lowerd1 Full Time Loser! Join Date: Feb 2003 Location: Murfreesboro Tennessee Posts: 65	I checked the Glove box and found the Options sheet but it doesn't say what the Rear end is. __________________ 1979 C10 - Its being rebuilt. 1978 Silverado - Its being driven. 1995 Grand Prix GTP - Its stock

09-26-2003, 10:06 PM	#4
gldevall Registered User Join Date: Mar 2003 Location: Walker, LA Posts: 2,925	If you have a tach, check your RPM's at 60 MPH and work backwords through a gear calculator __________________ Gary -1986 SWB: lowered 4/6, SOLD!!! -Best 1/4 mile: 14.51 @ 91.01 MPH -2001 Pewter Tahoe, billet grill, Corsa Sport Cat-back, K&N FIPK SOLD!!! -2004 Z-71 Extended cab with a flowmaster, BDS 6.5", 3" BL, 35x12.5x18 Trail Grapplers on Pro-Comp 18x9 wheels

09-26-2003, 10:33 PM	#6
Lowerd1 Full Time Loser! Join Date: Feb 2003 Location: Murfreesboro Tennessee Posts: 65	No Tach. I will check the Seat tomorrow. As for the Rear end I looked all over and I could not find it. I will look tomorrow again though. __________________ 1979 C10 - Its being rebuilt. 1978 Silverado - Its being driven. 1995 Grand Prix GTP - Its stock

09-26-2003, 10:12 PM	#5
N2TRUX Happy to be here Join Date: Mar 2000 Location: Cypress, TX Posts: 39,021	Does it have the original seat in it? There is sometimes a build sheet slipped in the springs under the seat. It may have it on there. According to the experts, it is on your rear end, but is hard to see. I have never verified mine, so I can't tell you where it's at exactly. If I remember correctly, it is stamped on the back side of the axle tube close to the pumpkin, and (maybe) on the right side...

09-27-2003, 04:59 AM	#7
Cole's 87 Registered User Join Date: Nov 2002 Posts: 272	Well if its time to change the oil in the rear end just count the teeth and divide the ring by the pinion gear ex: 37 teeth on ring 12 teeth on pinion =3.08 ratio

09-27-2003, 05:50 AM	#8
swervin ervin You get what you pay for Join Date: Dec 1999 Location: Cherryville, NC Posts: 4,798	You will have to clean everything real good to see it, but if you look on the passenger side axle tube, on the front side, about 4 to 6 inches out from the center section, there is a stamped code. It's small, about 1/8" or so in size. It's very hard to see sometimes as it was die punched and not cast into it. Anyway, if you can find this code, let me know what it is and I can tell you what it came with from the factory. __________________ Mike 1985 Chevy C-10



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