Newbie question I guess but what makes assembly lube so special? It just seems to me that instead of buying four ounce bottles to put a motor together there would be a very good supplement. Maybe a synthetic gear lube? just asking...

White lithium grease is typically used as assembly lube by professional engine builders on rod and main bearings and moly type lubes for flat tappet cam and lifters. What you are referring may not give you the best results for an assembly lube but maybe more for a "break in" additive. When synthetic oils first came on the scene, auto manufacturers warned and cautioned car owners about switching over to it from the traditional oils that came in the cars from the factory until beyond the recommended engine break-in period for fear it could cause problems with ring sealing and possibly voiding their warranties. Now synthetics are the norm. But I'm not going to promote any specific type of assembly lube or supplements for your engine, there are plenty of sources both good and bad that you'll have to research and decide for yourself.

Thanks for that, I guess I do need to do some research. The only motor I helped assemble was about 30 years ago when my Father and I put together a 390. From what I remember we just used 30 wt motor oil for everything. I put it in a truck and it had no problems what so ever.

White lithium is a old school way of assembly lube. No longer used in most shops. The problem with it, after aging it develops into a semi solid and plugs things such as lifters and galley ports to bearings. This is what I use.