360 Pushrods??

What length pushrods are you using on 360 with stock non-adjustable valve train and hydraylic cam. When I used 7.50" there was no pre-load. I found longer 7.520 and used them, but the engine still ticks because the preload is incorrect. One of my engine books, say that 7.534 pushrods are used on 360 engines, but Summit and Jegs just list 7.50 pushrods for 318/360 engine. Engine has Comp 280H magnum cam and 547 heads. :read2:
Thanks