Jbradley nailed...D60 has 9/16 bolts, the D44 has 1/2" IIRC. My bro-in-law (UTfball68) has a stock D60 under his 77...so they were out there, just few and far between. And yes the 250's had the gear driven 205's...which is usually the preference. The 203's were chain driven fulltime units which were prone to chain stretching and worse mpg's.