Torquemaster springs are made differently now than they used to be, so we don't have a double spring set for that size anymore. You will have to convert to a single spring setup. You can either upgrade to the plus style with the conversion kit we sell (includes all the parts needed for a single spring setup in the plus style), or you can reuse the winding cone from your old left spring as a spacer on the left side assembly. 

Original style double to single spring left side instructions: 

For Single Springs - No drive gear is required for left side. If converting from a double spring to a single spring, remove left spring and gears on left bracket. Left side will need a winding cone as a spacer to support assembly. Reuse old left spring cone or purchase one here - Torquemaster Left Winding Cone