Just pulled what I think is a Purpleshaft cam from a 440. Do the numbers 980709 or 930709 mean anything to any of you? What cam is this? Thanks!

Where do you see that number at. The purple cams I have , dont have anything like that.

What they do have in common is the number 1117 witch is cast into the base of the core. MP used the same 1117 core for alot of the purple cams, .509,.551,.590 etc.

If you dont see 1117 number cast into the core base you most likely dont have a purple cam.

Time to get out the mic and compare the Base circle to the max lift of the lobe. Mutiply that by 1.5 RRatio to get a approximate lift range for help to determine what you have. mikr

Thanks for the post! The 980709 is on the very rear face of the cam. (opposite end from timing gear) I don't see the four digit number you mention. Any other info guys? Thanks again 440!!

If it is a purple shaft there will be no identifying marks on it, you'll have to mic it.

Those numbers are lot numbers or something like that. They don't mean anything to anybody but the mfg.

Correct, they're numbers that are internal to the cam grinder out in Jackson MI and don't really mean much to anyone else.

When stock of non-suffix part numbers and AB part numbers runs out, the AC level cams will have P numbers on the back for easier ID. In most (but not all) cases the cam component PN is off by one digit from the packaged (with lifters) part number. Example: P4120663 and P4120663AB will have a gibberish number on the back, but P4120663AC will have a P number.

Finally, don't ever mic a .528, .557, .590, or .620 because .010 or more of lift can't be seen due to the clearance ramps required with a solid lifter. Hydraulics are OK to mic and reasonable accuracy can be attained, but the solids are best measured in a block, using a lifter and dial indicator.

Zippy. I feel you can reasonably measure the solids also.

Just now! I measured one of my two purple cams under my coffee table.

I know for sure one is a .590 and the other the .557 cam. Randomly selecting one and measuring both the "base circle compared the max lobe lift" I get these numbers.

1.5185 to 1.5195 max lobe height, left to right.
and a
1.1495 Base circle.

Since the lifter will react to the highest side of the lobe witch is 1.5195

1.5195 - 1.1495 x 1.5 rr = witch cam most likely.

MP .590 or MP .557 mike