Ditto on the "Welcome" Jay!! Looks like you've got a nice clean truck right from the gitgo!!! As Tim pointed out, the block casting numbers under and between the road draft tube and the fuel pump should help you lock in on the year of the engine.
Speaking of fuel pumps....I along with others have worked on solutions to the "leaking Rochesters" issue. Some of us have "jumped ship" and gone with Carter/Weber progressive 2 bbls. on our dual setups and some (the faithful) have stayed with their original equipment. One common thread that I've noted is that regardless of the type carb you're running, the addition of a fuel pressure regulator and a mini pressure gauge (from your local auto parts store) that adjusts the stock GM pump down to 3.5 psi cures the fuel dumping problem. No, it's not going to make a dirty carb in need of cleaning and a kit stop leaking, but it will improve your chances of salvaging the original equipment and driving with an engine that idles and accelerates without hesitation.
If you do a "search" of carb options, repairs and upgrades you'll see how others have cured the problem and get to enjoy their trucks as economical and fun drivers.
Once again, Welcome aboard!!!
Dave
