A 700R is 1.875 in. longer than a TH350, so swapping back to the older three-speed leaves the driveline short and the mount out of position. This aluminum spacer makes up that difference at the tailhousing, allowing a 2WD TH350 with a 6 in. tailhousing and a 15.5 in. output shaft to drop into a chassis that was built around a 700R.

Advance Adapters 50-8506 Installation Notes:

• Adapter spacer for replacing a GM 700R transmission with a TH350.
• Compensates for the 1.875 in. length difference between the two transmissions.
• Requires a 2WD TH350 with a 6 in. tailhousing and 15.5 in. overall output shaft length.
• Some modification of the tailshaft may be required.
• Hardware included. Sold individually.