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Atlas 27 spline input (GM)

GM 27 SPLINE:

The 27 spline Atlas was designed for transmissions with a 27 spline output. The TH350, Powerglide, 700R, and 4L60E transmissions are the most common GM transmissions equipped with this 27 spline output. These transmissions have various output shaft stickout lengths depending on the vehicle that the transmission was originally removed from.

TH350 4WD: When obtaining a TH350 out of a 4WD vehicle, the output shaft will protrude approximately 1" from the rear square flange of the transmission. An adapter housing (P/N AS-6800) can be purchased from us to use this transmission with this stock 27 spline 4WD output shaft.

TH350 2WD: When obtaining a TH350 out a 2WD vehicle, be aware that there are three different stickout lengths: 6, 9 & 12 inches. These transmissions would be better suited to either switch to a 4WD TH350 output shaft and use the adapter housing listed above, or use P/N 50-6300 (3.6" long). This kit require the installation of a new output shaft which switches the output spline to a 23 spline (See the 23 Spline section).

POWERGLIDE: The Powerglide automatic transmission has gained popularity in rock crawling vehicles. We offer a new cast aluminum adapter and crossmember mount designed to couple the Powerglide to the Atlas transfer case (Part No. 50-9200). The adapter kit requires a shorty 27 spline output shaft to be use when coupling the Powerglide to the Atlas. Two sources to obtain this shaft would be Hughes Performance or B & M.

700R & 4L60 4WD: When obtaining a 700R or 4L60 out of a 4WD vehicle, the output shaft should have a stickout length of 2.75" from the rear square flange of the transmission. Adapter housing P/N AS-9111 (2.5" long) can be purchased from us to use these transmissions with this stock 27 spline 4WD output shaft.

700R & 4L60 2WD: When obtaining a 700R out of a 2WD vehicle, the stock output shaft will be too long. These transmissions would be better suited to either switch to a 4WD 700R output shaft and use the adapter housing listed above, or use P/N 50-6303 (3.6" long), or P/N 50-9102 (1.5" long). Both of these kits require the installation of a new output shaft which switches the output spline to a 23 spline (See the 23 Spline section).

4L60E 4WD w/Non-Removable Bhsg: When obtaining a 4L60E out of a 4WD vehicle, the output shaft stickout length should be 2.75" from the rear square flange of the transmission. Adapter housing P/N AS-9111 (2.5" long) can be purchased from us to use this transmission with this stock 27 spline 4WD output shaft. Note: On these transmissions, you must use a reluctor kit, P/N 716073E.

4L60E 2WD & 4WD w/Non-Removable Bhsg: When obtaining a 4L60E out a 2WD vehicle, the stock output shaft will be too long; or if you have a 4WD transmission and would like to use an adapter housing with the reluctor as part of the kit, you can purchase P/N 50-0404 (4.6" long). This kit requires the installation of a new output shaft which switches the output spline to a 23 spline (See the 23 Spline section). This kit also incorporates a reluctor ring and sensor for proper transmission operation.

4L60E 4WD with Removable Bhsg: When obtaining a 4L60E out of a 4WD vehicle, the output shaft stickout length should be 4.438" from the rear hex bolt flange of the transmission. We offer kit P/N AS-9300 which adapts the hex bolt pattern to the Atlas. This adapter also provides a reluctor sensor and clamp-on reluctor ring.

4L60E 2WD with Removable Bhsg: When obtaining a 4L60E out of a 2WD vehicle, the stock output shaft will be too long. To use this transmission, you will be required to use P/N 50-0430 which adapts the hex bolt pattern to a square bolt pattern. This adapter also provides a reluctor sensor and clamp-on reluctor ring. To couple this tranny to the Atlas transfer case, this kit requires the installation of a new output shaft, switching the output shaft spline to a 23 spline (See the 23 Spline section).

SHORTY 4L60E ADAPTER with Removable Bhsg: We offer a shorty adapter for the Atlas . The adapter length of 1.625" is shorter than any of our other adapter options. This kit, P/N 50-9305, will use a 23 spline output shaft made out of 300M material. We also offer a complete transmission with our output shaft already installed. Please call for updated information and complete package pricing. The Atlas should be equipped with a STD. 23 spline input.

27 Spline Input For: 

Atlas 2 Left & Right Drop: A27 .250"  Transmission Shaft Stick out Length

Atlas 4 Speed: A4-27L (left drop) A4-27R (riight drop) Inputs accept .500"  Transmission Shaft Stick out Length

Stick out length is the length that the shaft protrudes from the rear of the transmission with the adapter installed. The measurement is the length that the Atlas will accept.