While pricing a new cam - the DC engine book says I need these springs.

P3412068 is different in these specs:

1.46 O.D.
.191 wire diameter
.520 - .620 cam lift range
135 lbs. closed
325 lbs. open

It should be easy to match up another manufacturers spring to the MP spring spec's. Look at Crane and Comp Cams or call if you don't find the on line specs.