273 Timing marks

I'm rebuilding a '65 273 and can't seem to find anything with timing marks on it. The timing chain cover doesn't have anything. Any one have an idea of what I need to look for? I bought a whole engine without a water pump and carb but it did have a timing cover. There is no evidence of ever having timing marks attached and neither do the 2 on e-bay. I've disassembled, cleaned it up and am now ready for assembly after appropriate machining, etc.
Anyone out there have an idea??