I'm rebuilding a manufactured in 64 283 that was in pieces when I got it. The manuals I have mention a thrust plate,but,I know the 350's have a thrust plate on the front of the engine but the 283 does not. Doe's the timing gear keep the cam from sliding back? What keeps the cam from sliding back and forth. I know there is a "button" that goes between the timing cover and gear,but,again, what goes between the back of the cam and the freeze plug?...if anything. Thanks.