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Transmission Info
Transmission Ratios : 1
| Transmission/Gear | 1st | 2nd | 3rd | 4th | 5th | 6th | Reverse | 
| Powerglide | 1.76 | 1.00 | - | - | - | - | 1.76 | 
| Powerglide | 1.82 | 1.00 | - | - | - | - | - | 
| TH200-4R | 2.74 | 1.57 | 1.00 | 0.67 | - | - | 2.07 | 
| TH350 | 2.52 | 1.52 | 1.00 | - | - | - | 1.93 | 
| TH400 | 2.48 | 1.48 | 1.00 | - | - | - | 2.00 | 
| TH700-R4 | 3.06 | 1.62 | 1.00 | 0.70 | - | - | 2.29 | 
| 4L60 / 4L60-E | 3.06 | 1.62 | 1.00 | 0.70 | - | - | - | 
| 4L80E / 4L80-E | 2.48 | 1.48 | 1.00 | 0.75 | - | - | - | 
| C4 & C6 | 2.46 | 1.46 | 1.00 | - | - | - | - | 
| 727 | 2.45 | 1.45 | 1.00 | - | - | - | - | 
| 904 | 2.70 | 1.54 | 1.00 | - | - | - | - | 
| Borg-Warner T56 | 2.97 | 1.94 | 1.35 | 1.00 | 0.84 | 0.62 | 3.38 | 
Overall First Gear Ratio :
1 (Tranny Ratio x Rear Gear Ratio)
| Tranny/Rear Gear | 2.41 | 2.56 | 2.73 | 3.08 | 3.23 | 3.31 | 3.42 | 3.55 | 3.70 | 3.73 | 3.91 | 4.10 | 4.56 | 
| PowerGlide | 4.24 | 4.51 | 4.80 | 5.42 | 5.68 | 5.83 | 6.02 | 6.25 | 6.51 | 6.56 | 6.88 | 7.22 | 8.03 | 
| TH200-4R | 6.60 | 7.01 | 7.48 | 8.44 | 8.85 | 9.07 | 9.37 | 9.73 | 10.14 | 10.22 | 10.71 | 11.23 | 12.49 | 
| TH350 | 6.07 | 6.45 | 6.88 | 7.76 | 8.14 | 8.34 | 8.62 | 8.95 | 9.32 | 9.40 | 9.85 | 10.33 | 11.49 | 
| TH400 | 5.98 | 6.34 | 6.77 | 7.64 | 8.01 | 8.21 | 8.48 | 8.80 | 9.18 | 9.25 | 9.70 | 10.17 | 11.31 | 
| TH700-R4 | 7.37 | 7.83 | 8.35 | 9.42 | 9.88 | 10.03 | 10.47 | 10.86 | 11.32 | 11.41 | 11.96 | 12.55 | 13.95 | 
| 4L80E | 5.98 | 6.35 | 6.77 | 7.64 | 8.01 | 8.21 | 8.48 | 8.80 | 9.18 | 9.25 | 9.70 | 10.17 | 11.31 | 
| Borg-Warner T56 | 7.16 | 7.60 | 8.11 | 9.15 | 9.59 | 9.83 | 10.16 | 10.54 | 10.99 | 11.08 | 11.61 | 12.18 | 13.54 | 
Overall Second Gear Ratio : 1 (Tranny Ratio x Rear Gear Ratio)
| Tranny/Rear Gear | 2.41 | 2.56 | 2.73 | 3.08 | 3.23 | 3.31 | 3.42 | 3.55 | 3.70 | 3.73 | 3.91 | 4.10 | 4.56 | 
| PowerGlide | 2.41 | 2.56 | 2.73 | 3.08 | 3.23 | 3.31 | 3.42 | 3.55 | 3.70 | 3.73 | 3.91 | 4.10 | 4.56 | 
| TH200-4R | 3.78 | 4.02 | 4.29 | 4.84 | 5.07 | 5.20 | 5.37 | 5.57 | 5.81 | 5.86 | 6.14 | 6.44 | 7.16 | 
| TH350 | 3.66 | 3.89 | 4.15 | 4.68 | 4.91 | 5.03 | 5.20 | 5.40 | 5.62 | 5.67 | 5.94 | 6.23 | 6.93 | 
| TH400 | 3.57 | 3.79 | 4.04 | 4.56 | 4.78 | 4.90 | 5.06 | 5.25 | 5.48 | 5.52 | 5.79 | 6.07 | 6.75 | 
| TH700-R4 | 3.90 | 4.15 | 4.42 | 4.99 | 5.23 | 5.36 | 5.54 | 5.75 | 5.99 | 6.04 | 6.33 | 6.64 | 7.39 | 
| 4L80E | 3.57 | 3.79 | 4.04 | 4.56 | 4.78 | 4.90 | 5.06 | 5.25 | 5.48 | 5.52 | 5.79 | 6.07 | 6.75 | 
| Borg-Warner T56 | 4.68 | 4.97 | 5.30 | 5.98 | 6.27 | 6.42 | 6.63 | 6.89 | 7.18 | 7.24 | 7.59 | 7.95 | 8.85 | 
General Tranny Swap Info:
- TH375, TH350, Powerglide, TH200-4R, TH700-R4, and Muncie M21 all have the same 27-spline output shaft.
- TH400 has a 32-spline output shaft.
- TH350 and TH200-4R use the same yoke.
- TH700-R4 is 3" longer than the TH350 short tail.
- TH700-R4's rear mount is 2" to the rear of that of the TH350 short tail.
- Swapping from a TH350 short tail to a TH700-R4 will require shortening the driveshaft 3".
- TH350, Powerglide, and M21 all have the same length and output shaft spline count - therefore, no driveshaft mods required when swapping.
- TH350, M21, TH200-4R, and TH700-R4 all use the same tranny mount, but TH200-4R and TH700-R4 use metric fasteners (M10 x 1.5 x proper length).
- Shims may be needed when swapping TH200-R4 in place of TH350 (or any tranny swap, for that matter) for driveshaft phasing.
- Transmission mount or crossmember may need to be relocated fore or aft for any given swap.
- TH200-4R and TH700-R4 have lock-up torque converters (from the factory) and thus no top gear slippage when locked.
- M21, TH350, and Powerglide all fit the '68-'74 Nova without modifications, and the TH400 should, too, since they were available from the factory.
General TH200-4R vs. TH700-R4 Information:
- TH200-4R has universal CBOP bellhousing bolt pattern, while the TH700-R4 has the Chevy only pattern.
- TH200-4Rs offers full-throttle upshifts into overdrive, while only '91 and later Corvette TH700-R4s offer this.
- When built properly, both trannys can withstand a lot of power! In the neighborhood of 650-700 hp.
- The 4L60 is the same as the TH700-R4. The 4L60-E is also the same, but electronically controlled.
- The best source for TH200-4Rs is from Buick GNs and T-Types.
- Non-lock-up torque converters are recommended for durability and to avoid some problems.
- Use only '87 and newer TH700-R4. They are much stronger than the early versions.
- Use only '86-'88 TH200-4R.
Copyright © 2009 Bruce Johnson and Craig Watson




