Fitting a Pontiac SOHC 6 Sprint engine, 2004R AT in my 1938 Pontiac. Intend to retain existing 4.10 diff. The yoke on the diff uses "bushed" u joint and the 2004R yoke has a needle bearing u joint. My goal is not performance, rather to make a inline Pontiac powered driver from a nice survivor. Are there any alternatives (other than changing rear end) to a driveshaft with a bushed and needle bearing at opposite ends? What are the problems with such a mismatch? Bill Gardnerville, NV
I wouldn't be surprised if a 55-57 Pontiac rearend will bolt on your springs with no mods and only you would know the difference. I don't know why the two wouldn't work together, though, as long as the angles are all correct.
Time to visit a driveshaft shop. Should not be a major deal to change one or the other end yokes on the shaft/tube. As far as the "bushed" joint goes I'll bet there is a needle bearing one that will replace it. My ujoint catalog only goes back to '40.
Totally not a problem. I've run the original rear under the '51 wagon, with a yoke on the front end of the original driveshaft to accept the 4L60E trans yoke and cross, and my '48 Pontiac 'vert had the original rear for a while behind the Cad 472. Any driveshaft shop can make you up a new shaft with your cars rear yoke and whatever it needs to mate to the newer trans. Great idea, you'll love the result.
I intend to run the original 48 rear under mine with a 700 up front. Only change I'm making is using a 56 Olds punkin. 48 Poncho