Has anyone used Fastenal for inexpensive shipping of large, heavy car parts (like engine blocks and transmissions)?
Yes, Fastenal! The bolt and screw stores!
Apparently they offer a service whereby their trucks will ship your items (if packed and brought to the nearest Fastenal store). When one of their trucks is half full, they fill it up with customers' items to ship. It goes to the Fastenal store nearest your destination. If it's heavy, therefore, make sure that the receiving and the shipping stores have a lift truck to get it off / on your truck at either end. Prices are apparently much less than USPS, Fedex, or UPS. And with heavy items like engine blocks, it appears that you can simply strap them to a wooden pallet, you don't need to build an expensive crate for them.
Because they depend on spare space in their trucks, to ship items, you may be pushed to the back of the line. No expedited or 3-day ground service, here! But if you are willing to wait, you can save some money!
I know nothing more, except that -- on the couple of websites where I saw this mentioned -- those who had used Fastenal seemed to be pretty happy with it. Here is a discussion on the Model T Forum: http://www.mtfca.com/discus/messages/411944/496104.html
. And the Model A folks: http://www.fordbarn.com/forum/showthread.php?p=701840