I have a 10 spline SM465 and NP205. They are in could shape, but the coupler has a little play in it. I understand the coupler wears more than the shafts might. Would it be prudent to just replace the coupler? I have about 300hp and 550 FT lbs of torque at low rpm. Should I worry about the weakness of the 10 spline setup, or get a 32 spline SM465 and have the NP203 GRB fixed for 32 spline and the round bolt pattern? If so, how much does it cost to have the NP203 machined and the parts for it? Bottom line, is the 10 spline SM465 really that weak? To run the doubler, the NP205 has to be the turbo 400 version. I have a Dodge turbo Diesel model 32 spline with the round bolt pattern. Will this work on the new doubler?