I agree with LONGBOX55, don't use a turbo 350. At 60 mph, you will be turning high RPM's. A TH700R4 will give you an overdrive gear and you should be able to run 70 mph at about 2400 RPM's with a rear end gear ratio of 3.55. For a 235, that is very comfortable. With the Buffalo Enterprises adapter, it makes a nice finished product.

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