Hi Daryl,
Could not help but notice your post - because I also have a '76 C30.
Here is a link to a company I highly recommend for trailer hitches....
http://www.etrailer

/hitch-1976_Chevrolet_C%2FK+Series+Pickup.htm
You can shop, choose, and determine what suits your needs. Buy enough and you get free shipping.
I would recommend a Class IV since you may tow a '47 Chevy and when looking at electronic brake controllers - consider the Tekonsha PRODIGY. It is an outstanding controller with several nice features that come in handy when towing empty or going for the "full load".
One last tip.... when installing the hitch you may want to consider using highly quality American made fasteners with a Grade 8 rating. I have seen too many CHINESE bolts fail due to poor material, or grading and that is the last thing you need when towing a trailer.