70, the edelbrock carb is by far the easiest carb to rebuild on the planet. Do it yourself! First step is to loosen the two screws on top of carb that hold down small round covers the size of a dime. Once these are loose, swing them to the side and the metering rods will pop up. Pull the rods and spring under each piston. Set aside. Now unhook clip on accel pump. remove the screws holding the top on carb. gently remove top being careful not to trash bowl gasket. Set top and gasket aside. There will be primary jets where the metering rods went into carb. Remove primary jets(note size), then remove secondary jets(note size). Now remove air/fuel screws and set aside. Blow through main and secondary jets as well as air/fuel screw holes. Blow out accel pump passage. Look for crap in passage or in jets. Reassemble backwards, installing metering rods last. The rods may try and hang up when you put them in well, if they do, lightly tap with your finger until they go down into well. Metering rod fits into jet and may need a bit of jiggling to get it to drop in.
I have rebuilt and jetted hundreds or AFB style carbs and they are dirt simple. The way they work is that when vacuum is high, it pulls the piston down placing the thick part of the rod in the jet leaning it out. When you step on the gas, the spring under the piston overcomes vacuum and it pulls the rod upto the second diameter of the rod richening the mix. The secondary circuit is just jets that get vacuum when the secondary's are opened by depressing throttle about half way. The Air/fuel mix screws are easy as well, turn them in by hand until they bottom out, but dont tighten them. Then back them out 1 1/2 turns. When you have it up and running again, turn screws in and out one at a time. Listen for rpm to increase or decrease. Make your adjustments smaller and smaller until you get them in the middle of raising rpm and lowering rpm. Thats all there is to a AFB type of carb. Jetting is really easy too, rods have two measurements, thich part and thin part. you can get rods in many diameters to fine tune. Jet for mid throttle on primary circuit then change rods to get idle/low throttle mix correct. Some carter's have 3 step rods but shouldnt apply to your situation. If you run into problems, you can pm me with questions. If you have junk in bowls, get a finer fuel filter ie smaller numbers smaller screen. 30 au(microns) is good.
Once its running, go get your money back from shop that screwed it up....
You can also buy a book from Amazon for $15 that goes over them step by step.
