67 Gto bucking in first and second
 

I took my goat out the other day for the first time in about 2 years. I had a wheel come off 2 years ago and due to lack of funds lost interest for a while. In that time period I replaced the gas tank, fuel pump, fuel filter and rubber hoses. The car started right up no problem, idled very nicely, and I was pretty happy since it was the first start up since the fall. Decided to take it out for a quick spin around the block and it was bucking wildly. Initially I thought maybe i put it into a wrong gear or something but it wasn't. Was just bucking back and fourth constantly, even into second. When I would clutch the engine would be fine and the bucking would stop. So what kind of problem am I looking at here, engine or transmission? I have searched and heard to check the points but I have a gm hei distributor. The car needs an oil change and probably plugs, although the plugs don't have many miles on them the car has been sitting.

I also don't have my fuel gauge hooked up, and was wondering what type of connector attaches to the sending unit. The car didn't have it hooked up when I bought it, so all that is under there is what looks like the correct severed wire to the fuel gauge. If anybody has a picture of what theirs looks like that would be a tremendous help.
Thanks in advance for your help!

-Brian

Could be a carb problem from sitting so long. or a vacuum leak. check the accelerator pump for a good strong squirt.