'69 Going dead when I put it into gear?

Your problem is a vacuum line, most likely. Check your vacuum system, first to the transmission, then to the power brake booster, then to the vacuum reservoir, then from the reservoir to the heating/air conditioning vent system. You should find a hose loose or leaking somewhere. The short line attached to the transmission modulator valve is frequently the culprit. It can get fluid soaked and soften up to the point it cannot seal properly.
If nothing is found in the lines, check for a vacuum leak around the carb by spraying carb cleaner on base of carb with motor running. The idle will change noticeably when you spray the cleaner on the leak area.
Best,
Al

I had a similar issue on my 67...I'm not exactly sure what fixed it, since we changed out the spark plugs (which were old), distributor cap/rotor, and spark plug cables. One end of the short cable going from the distributor to the ignition coil (or what I think is the coil) was all corroded. We swapped out the cable, and the problem went away. Maybe check that?

I think Al covered everything that would cause your problem. One thing I noticed about my transmission modulator hose and hard line today was that the hose fit tight on the modulator but then I noticed it was loose on the hard line. I got a clamp and tightened it up and it has smoothed out the last bit of roughness I have been experiencing lately.
Dave

Yea actually come to think of it.. right before we took off for the first drive we have taken in it I did notice a small hard line coming right out the front of the carburetor that had no line attached to it and it looked as though fog was coming out of it. If looking at the carburetor from a front view, its a 400cfm 4barrer holley if it helps, and right under the float on the left hand side is the hardline I'm talking about. I don't really have the knowledge you guys have about carburetors yet, and I've been looking for a book or somewhere online for a full diagram but have yet to find one... Happen to know what hardline little valve/hardline I'm talking about? If not I can go out to the shop and snap a photo real quick.
-Taylor

Sounds like the vacuum line that should attach to the vacuum advance module on the distributor. Even though the line should be attached for proper performance, I don't think that line's being off should cause the motor to die. The vacuum source used is ported vacuum and not engine vacuum. Look on the lower part of the front of the carb under the float bowl on the right and see if you can locate another similar fitting. That fitting should be capped with probably a rubber cap.
Best,
Al

Are you sure the battery cables are good? And clamps tight?

Just bringing that up as I changed a battery out once and the car started and idled fine but stalled when I put it in gear and tried to pull forward. After 15 minutes of head scratching I found I forgot to tighten the battery cable clamps. If one of the cables is corroded inside the shielding, that could cause the same symptom.

Guys I think I figured it out I appreciate the help, more specifically Mr. Al. I'll throw a picture on here to show you which valve I was talking about I believe that it is a PCV? That happened to be an extra on the front not being used because there is a similar on the rear float of the carb that runs to the left valve cover. I fooled around a little bit with the idle, and capped it off, and she seemed to hold an idle fine when I put it in gear now.

/Users/dothedew2014/Library/Application Support/iLifeAssetManagement/assets/sub/01c7991800783caba217899cca0ab62e1c9b89d6a3/IMG_0244.JPG