I have a bog I can't seem to find on a 74 Challenger with 360. Here's what I know. Car has new carb and distributor. Someone installed HEI style distributor. Car has dual plane intake and 670 Holley. All new. Car runs perfect in park/neutral. Revs great...sounds awesome. Problem is car won't get out of it's own way in gear. Seems almost like it has a rev limiter when it is gear limiting it to around 2000 - 3000 rpms.

Basics.. Car has proper fuel pressure/volume (gauge). Timing advances perfect when in neutral/park. Timing doesn't seem to advance properly when car is in gear. I've taken distributor out and replaced with original style and still problem exits. Car holds great vacuum at idle (no leaks). I've change hot wire to distributor and still problem exists.

If this were a GM I'd be looking for a bad modulator on transmission or some reason this gear bogs so bad in gear.

What am I missing???? What can cause this problem when car is placed in gear?

It wont rev past 2 or 3K in gear? or it revs too slowly? How are you checking the advance rate?

No tach on car so I don't know the exact rpm where it bogs and dies. But it is less than 3K. You cannot power brake car....it will die. I put timing light on car. It advances fine in park. Once placed in gear and put under load the timing will not advance....timing actually retards and car bogs and will die. I've watched rate of timing advance and total timing.

Vacuum advance?

If so is it disconnected when doing this? It should be disconnected.

I'd set the timing at 14* at idle to start and then check where you total falls in park revving it up. YOu may need to alter the mechanical advance.

Yes it has vacuum advance. I've tested with advance connected and disconnected. Same result. Car will not rev and dies under load. Could this be something in the distributor causing to bog under load? It's strange because car has no problem revving in park. Only in gear and under load.

accelerator pump linkage?