i believe the large letters are the year.the man to contact on this would be duane heckman ,he goes by DUANE on here.he could tell you :TU:
Manuals are pretty easy to find on evil bay..Usually buy it now at 19.95..Worth every penny!! There is also a company that is usually at every big swap meet I am ever at.. Randy http://cgi.ebay.com/ebaymotors/1970...300035291941QQrdZ1QQsspagenameZWDVWQQtcZphoto
the two large letters on the tag is the code for the whole radiator assy. the two pairs of smallier letter codes are the codes for the tanks. the date code is hand stamped on the bottom of the tag.
