I'm getting everything together to install a C4 in my 55 and am starting to think, or maybe over-think the driveshaft. I know the difference in the rear u-joint. but the front is different also. Is there a difference in the u-joint size between a 55 and 56? A quick measurement near the differential showed the driveshaft to be 2 in. in diameter which seems small and I was wondering if the 56 was larger.

I guess the short version is there a great enough advantage to updating the differential yoke, or just take my existing driveshaft and a C4 yoke into the machine shop and have them put every thing together when I get it lengthened. I'm not planning on any real racing, but might continue to warm up the existing 312 just a little with headers and a mild cam.



Thanks,

Don