I had used Houston Drivetrain for 30 years w/no problems. The last shaft I had them make(6/10) took them three tries to get right and I had even gone so far as to print off a sheet from Denny's driveshafts with all measurements in hope of preventing just this. When it developed a vibration after 5k miles they fixed it but tried to tell me that heat from my TTI exhaust had warped it! We put a Dana in my buddies car and they screwed up on shortening his shaft also, it took two tries. They used to have some sharp folks there, but I am finding another shop.