engine chuggin

Water pump inlet changed for 1970, as did the timing cover and crank damper. They should be matched to prevent confusion. An early (iron) water pump on a later timing cover make the timing marks difficult to see. A later (aluminum) water pump on an early cover make them darn near impossible. An early damper with a late cover or vice-versa make the marks meaningless.

At this point my advice is to make sure everything is lined up correctly with #1 cylinder at TDC. So first you need to make sure the PISTON is at TDC. A piston stop makes this easier, but it can be done with a screwdriver in the spark plug hole. Once the piston is at TDC then you can verify your mark on the damper. If it's the original 1968 damper the chances are pretty good that the outer ring has moved. That doesn't matter, make new marks with a sharpie. Then verify that your distributor is installed correctly. That is, the rotor should point towards the left front intake bolt, and the advance should point more or less to the antenna hole in the fender. If the rotor, or more specifically the drive slot in the intermediate shaft does not point at the left forward intake bolt the shaft has been installed wrong (or the valve timing is off). You also want the rotor to be pointing at the #1 wire on the cap. You may have to shift the wires on the cap. The reluctor should be just slightly past the center of the pickup. Now the engine is mechanically timed enough to start and idle. Now is also a good time to make sure the mechanical advance is free. Twist the rotor clockwise. It should turn about 10 degrees and then spring back when released.

Next, get the carb to a good starting point. Disconnect the vacuum hose to the advance and cap the nipple on the carb (right side). All other vacuum lines (PCV, booster, heater control) should be connected, and any unused nipples capped. Set each idle mixture screw 2 turns out. The engine should start and idle.

Start the engine and adjust the idle speed as needed to get it to keep running. Use a timing light to see where you are now, should be close to TDC. If you have an accurate mark, set something reasonable like 10 degrees BTDC for a stock 318. Trim idle mix and speed as needed, you should be able to get a smooth idle at 800 RPM or so. If you determined your marks were off, or they're hard to see set the timing by ear. To do this, advance the distributor (counter clockwise) to the highest idle RPM and then back it off just a little. Trim idle mix and speed as needed, you should be able to get a smooth idle at 800 RPM or so. If you haven't verified the float levels in the carb, now would be a good time to do so.

Now, with a reasonable timing baseline set, and the carb adjusted well enough to idle smooth take a test drive. Leave the vacuum advance disconnected and capped at the carb. The car should drive OK with no major bogs or stumbles at light to mid throttle. I wouldn't expect stellar throttle response just yet, but it should be driveable. Driveable enough to go to the store and buy a vacuum gauge.

Once you get this far report back and we'll help you get it dialed in better.