Manual Transmission Gear Ratio Charts for GM/Chevy Vehicles
Gear ratio affects a variety of driveline combinations, so it’s important to know what the gear ratios are for a gearbox you might be swapping into your ride. (Image/YourMechanic)
Because different transmission gear ratios can greatly affect a drivetrain combination, it’s important for anyone performing a transmission swap to know the gear ratios of the gearboxes you might be installing in your vehicle.
We’ve assembled a variety of manual gear ratio charts for General Motors vehicles that we hope can help you avoid choosing the wrong transmission only to discover your hot rod or truck is performing like a 19th-century horse-drawn chuckwagon, minus the delicous beans and salt pork.
Planning a manual transmission swap in your Chevy or GM vehicle? Double-check your gear ratios. Here’s a good start.
[NOTE: Not every transmission in GM’s history is listed here. It is mostly Camaro/Firebird/Corvette-focused. We’re sorry if you love a particular transmission not shown on this list. We promise it wasn’t intended as any sort of slight to the excluded GM-made transmissions.]
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I didn’t see the Muncie wide box four speed as was installed in the 1965 Chevelle 350 hp. 327 cars.
I ran a M-21 in my Big block Chevelle with 3:55 gears. Great torque. I was shifting into 3rd around town. I then swapped a 454 in and I run an M-20 and it is much better all around. Great low but not so great highway speed. 3500 T 65 mph or so. Gear Venders is in the future
How about the T&C HD 3-speed – yes, a Ford box, which was the base transmission in pretty much every GM musclecar? 1970 Buick GS455 had it…
Saginaw was widely used in Pontiac and Chevy small and mid sized cars including Tempest and Camaro (among others) you totally dropped the ball on Saginaws, here’s the whole story. Saginaw 3-speed
No Lines (grooves)
2.85
1.68
1.00
1 Line
2.54
1.50
1.00
2 Lines
3.11
1.84
1.00
3 Lines
3.50
1.89
1.00
Saginaw 4-speed
No lines
2.84
2.01
1.35
1.00
1 Line
2.54
1.80
1.44
1.00
2 Lines
3.11
2.20
1.47
1.00
3 Lines
3.50
2.47
1.65
1.00
Read more: Transmission Ratios Chart http://www.roadkillcustoms.com/hot-rods-rat-rods/garage-shop-reference-Transmission-Ratios.asp#ixzz4wwRJejBN
Hi there
Are you aware if Chevy 1/2 ton trucks from 1980 to about 1985 were fitted with overdrive A833 New Process transmissions?
Thanks