I have a 302 mostly stock. It has a trick flow track heat intake and 75mm throttle body, swapped to maf and updated a9 ecu. Just bought some flow tech 180 heads and an Anderson n41 cam. What length pushrods do I need? What lifters? What degree does the cam need be? If I use arp head bolts, do I need to drill and tap the block? Will the heads I have get enough valve clearance or will I have to shave and gouge the block a little to make them work? Any advice would be great!