Welcome to the 'bolt Paul! I'm somewhat new myself, but don't have a truck (yet). Getting the weight is going to be a little tough given that it is a dump truck. Some guys on here might be able to help you out with the weight of the chassis, cab, etc., but adding the dump bed will be the tricky part.
On the other hand! Congratulations on getting your bolt. Its always good to hear a story that goes with a piece of equipment no matter what it is (I'm also into Allis Chalmers farm equipment). Good luck on your endeavor to get her running. How bad is it? Do you know what exactly is wrong? Do you have any pictures to submit to the gallery? No matter what it is, you came to the right place. Everyone here will be able to answer your questions as long as your patient.
Also, if your in need of parts, there is a very good source that I have heard of and my dad has met. I have not dealt business with him yet, however he has been VERY helpful before I have even had a truck. His website is oldchevytrucks.com. It looks like he has just about anything you could ever need...AND WANT!!! LOL.
Again, welcome to the 'bolt!
