Ive had 3 different carbs on it. 2 Thermoquads, and one 600 Edelbrock. The Edelbrock did have a bit more low end and pulled maybe 1" of vacuum more than the Thermoquads. Also, I forgot to add...I did advance the cam 2* to 104 and the only thing it did was kill my gas mileage. Im drawing a blank here

Something is VERY wrong. Did you fix or check the balancer issue?

There is NO REASON that camshaft shouldn't idle at 750-850 rpm with a 50-75 rpm drop in gear.

If the timing is correct, I bet there's a vacuum leak somewhere.

Where could a vacuum leak be though? I changed the carb, the manifold, and it dies when you choke it. Im not sure how a vacuum leak would cause such low numbers on a compression test either. Unless thats all a sub-8.0:1 with this cam will do. Could this cam bleed off enough cylinder pressure to do that based on the specs of the cam?

Your compression does not sound bad, your motor is very low compression ratio and will not pump up big numbers unless you put something with VERY short .050 duratio in it. I had a stock cam from a 273 2bbl in my 318 with 10.0 compression and it pulled 20 inches vaccume so your vaccume is not the end of the world.

I think your carb or ignition is the problem

Reading back over every thing it looks like your distributer is advancing too fast anmd probably too much. That motor will want a lot of initial advance like 18 degrees minimum, of course now it will run like crap if you do that because it is advancing it too much too early. You need to take apart the distributer and put stiffer springs in it. Also can probably put in a shorter advance plate so you get less total witch since you are advancing the initial will really keep the total about the same. Your motor will want a lot of initial but not too much total like mabey 36-38 total. If you do tha math you start with 38 and subtract 18 for the initial you have 20 left you need to get mechanically so you plate should say 10 degrees on it witch will give you 20 degrees at the crank. You need tight springs so it don't start advancing until 1000 and max out at about 2000-2200.

You need to put the distributer to rest once and for all and eliminate it as the problem.

After that you can move on to a carb problem. Your motor will probably end up makeing more vacume than any of those carbs were desighned to handle so the idle circuits will need some modifying. I noticed my motor always wanted more fuel at idle than the carter carbs both TQs and AFBs would give it. Don't give up though they can be fixed but eliminate the distributers timing curve first.

Why not leave the timing where it ran best (advanced) and put in a good strong mini starter to get it started?? I had a stock starter on my 408 and it just wouldn't start. Put a mini starter in and voila! no problem!

Low compression readings can also come from a weak starting system. Are the cables new? Battery the biggest you can fit? I havent used a factory old-type starter in 10 years. The remans are terrible in most cases so I either get a used factory Magnum one or buy the brand new MP unit. You will not have to buy another one once you do that. I also think you need to verify TDC because it sounds like the balancer is junk. At least make a single mark over the inner ring, rubber, and outer ring and see if it's moving around at all after driving it hard. That cam should have another 5-8° at idle and idle speed should be down near 650. I think perhaps the lean burn Thermoquad carb needs some work too to run properly.

Wow, thanks for all of the replies! It looks like I have some tuning to do. I called Comp, and they also said this cam should have way more vacuum than this. So the plate in the distributor will actually have a number on it as stated above? I have a box of distributors up in the crawlspace that I can search through. Can I use two factory stiff springs, or are those too strong? As far as the battery goes, it is a 6 month old group 27, and the starter is the longer factory style starter that was in my 11.2:1 360 in my Barracuda for a while. Im gonna go out and mess with that ignition timing and see what I can come up with

Patrick and Mopart guys, i'm having the same no low end torque problem also. I have a 68 dart 383. It is pretty much stock but bored 30 over, schumacher headers, 383 torker mainifold with a new holley 770 avenger carb, new Comp. XE274 cam and lifters, stock heads ported and polished with HD springs, new pushrods, rebuilt 727 trans, 323 sure grip and 3000 hughes stall converter, stock elct. ignition with orange ECU box. Everything is pretty much new in the motor compressions good, vac.is good but it's totally a dog on the low end out of the hole. the motor runs great and it seems to make good power but it just seems like its not getting the power to the rear wheels at launch. I'm starting to think the new in the box stall converter which i bought from a friend may be clogged or have trash in it. Any suggestions would greatly be appreciated. I have gotten pretty frustrated and don't want to just throw more money at it and hope the problem gets solved. Thanks.

Patrick and Mopart guys, i'm having the same no low end torque problem also. I have a 68 dart 383. It is pretty much stock but bored 30 over, schumacher headers, 383 torker mainifold with a new holley 770 avenger carb, new Comp. XE274 cam and lifters, stock heads ported and polished with HD springs, new pushrods, rebuilt 727 trans, 323 sure grip and 3000 hughes stall converter, stock elct. ignition with orange ECU box. Everything is pretty much new in the motor compressions good, vac.is good but it's totally a dog on the low end out of the hole. the motor runs great and it seems to make good power but it just seems like its not getting the power to the rear wheels at launch. I'm starting to think the new in the box stall converter which i bought from a friend may be clogged or have trash in it. Any suggestions would greatly be appreciated. I have gotten pretty frustrated and don't want to just throw more money at it and hope the problem gets solved. Thanks.

Mine ended up being the carb

Here's a chart

yea i pulled the edelbrock perf. carb. 650 off my brothers 68 cuda and it made minimal difference. I have a new aveng. 770 holley on it now with hardly any changes in the low end.

approx. 9.5-1 to 10-1 comp. 12 degrees intl. and 14 vac.

the initial & vac sound good. Do you know what your cranking compression is? EDIT Probably more inportant than the CC, I missed the 3.23's which are hurting you and what is your curve

yea i know the 323 gears are hurting some, but this little A-body should still be launching pretty hard. Got buddys with 383 roadrunners with 323 gears and there launches are very stout compared to this A-body.

Thanks for you help, We have gone through alot of things on this with alot of hard work and no results, i have a lokar cable system for the throttle and kick down and have looked at that also due to kick down issues. I'll just keep plugging away on this, i really thinks it's something real simple that i;m overlooking.
thanks again.