cam swap
Mrspeeddemon,
The cam brg. book that I have shows the 57-79 cam brgs. take a different brg. than the newer version as the counter bore is 2.130 with a .875 length and a .0645 thickness. On 4 out of the 5 that they take. The newer brgs. are for 80-99 shows 3 different counter bores depending on the position which are, 2.0830, 2.0990, and 2.130 with the length of them varying from .615 to .625 with one at .930, and the thickness of .645. So I would have to believe the manufacturer is correct as they get there specs from Chrysler to make the brgs.. Also the eariler brgs. have oil holes for the heads to get oil to the rockers and the magnums don't as they oil through the lifters like a chevy, thus the oil passage in the block is blocked, or not drilled.
If you have a magnum block with a older set of cam brgs. in it then someone had to have done some reaming on the brgs. as they should have been very tight just due to the counter bore size being different.
If the counter bore is different in the block and the brgs. are the same thickness then the cam has to reflect the change also. The journals are thinner than the earilier versions also, so if what your saying is true then the newer cam should fit in the older block which maybe true but the oil pressure would be lacking due to too much clearence.
BJR Racing