All timing chains like yours can be installed without setting the timing marks on #1 TDC. There are timing marks on the sprockets. Maybe the marks line up better by doing that first but I never bothered. I never had any problem moving the crankshaft or camshaft into position on that old style of engine. Of course, doing whatever the manual says to do is best. That engine should be really easy. Wish I were there, I like coming in after most of the work is done to grab some of the glory.