I am building 406, but when putting motor back together with new 5.7 rods having clearance problem with cam.I was told by local machine shop that all my rods that I installed arp bolts,needed to have there heads grinded off to clear cam will that effect there integrity?  

or you can buy a small base circle cam.  At least with roller cams, i'm not sure if they do it with other cams, I ordered mine with a .900 base circle to clear the rods.  

I'm not a big fan of grinding the bolt heads on conventional rods that use headed bolts as opposed to rods that use cap screws. However, lots of people do it and are running fine with this proceedure.

The alternatives are to use a small base circle cam, a raised cam Rocket block, or cap screw rods, none of these is inexpensive from where you are right now.

Bogie