My 72 convertible was a 350/350 car. Just finished pulling them for a 455/400 combo with a chebby 12 bolt posi. I know I need a yoke but will a stock driveline from a 68 to 72 cutlass or 442 direct bolt in? Anyone know the exact measurement or other options besides modifying mine?

 

You may need different Ujoints to bolt to the 12 bolt. I know the driveshaft will need to be modified or you can probably use one that's for a T400. The trans cross member will need to be moved back about 6 inches, the mounting holes should be in the frame. You'll need a kickdown switch and wiring. Most replace the front and intermediate e-brake cables for a T400 location of the xmember.

 

You need a driveshaft from a 68-72 A-body 2dr with a TH400 and a Chevy 12 bolt. The corporate 10 bolt that was stock in that car has a different pinion flange to axle centerline distance than does the 12 bolt. Most likely you'll need to look for that driveshaft under a Chevelle, not a Cutlass (unless it's a Canadian-built 68-69 Cutlass).