Hello. My 426 is tuned with a Wiseco high compression piston and Hotcams and a carburator Kit. I was very pleased with the results but recently my fifht gear failed. Since i am from Portugal, do US models soffer from such problem? It seems that the material on wich the gears are made is not very reliable, but almost everyone experienced problems only in fifht gear. Now...back to the issue, is there any manufacturer that sells a kit to raise the displacement of the 426 engine? My goal is not max HP but monster torque. Thanks fo the help.