With a 650CFM carb, probably jetted too big for your 318, which likely has a ton of miles on it.  Just swapping a carb on a stock 318 will not net you much 'seat of the pants' power. 
Did you change out the kickdown linkage for the trans when you changed the carb?  4bbl uses a different linkage and if not adjusted properly, will cook your trans in little time.

If you wanted more seat of the pants power, should have started with axle gears instead.

 

did you hook the kick down linkage up? the reason you may not notice much of a power difference is because you got a carb that is way too big especially for a stock engine. something in the 400cfm area would have been way better for a truck 318.

 

To be honest I did not do the work, I had a shop do the install, I will have to find out about the linkage.  Is there a way to adjust it or is there an aftermarket setup i have to get?  In researching on Summit, Holley, and other websites everything pointed to the 650, that's why I went with it.  On the Holley website the 450 is for 4 or 6 cylinders, so i never even considered it.

As far as the gears, that's the next upgrade, but I also want to install the lockers front and back along with the 4x4 posi-lock for the front, but parts alone are over a grand, and that's not including the install $$ so that's in the works, hopefully by the end of the year.

Thanks again for any additional thoughts!

 

when I got my holly truck avenger it was jetted for sea level and I was in colorado way to much fuel for there after putting in smaller jets it had power and mileage 17.5 mpg in a 74 360 trailduster to be exact

 

In doing a quick search online I found bouchillonperformance has a Kickdown cable kit.  I think i'll look into that.

Is the carb really too big?  Can I change to the smaller jets, will that do anything?

In building this thing I've been very picky as to what gets changed or installed and I thought I was doing the right thing to make this an all around well performing truck.  I'm realistic, and I didn't think this was going to turn into a race vehicle or anything.  I just wanted to swap it out maily because of the stalling I was having when climbing, the benefit of a little added performance was just a bonus.  Now I feel like it won't make it climbing the smallest of hills. 

 

http://www.holley.com/data/TechService/Technical/Selecting%20A%20Carburetor.pdf

how about you read this and decide if you went too big.

 

this is why l keep say,in dont bother with a 4bbl on a 318  / the motor is designed for torque and the heads are just to small to make power and if you put 360 heads on then the bore is to small

 

Also don't drive it until the TV cable (kickdown) is sorted out or you will be rebuilding the trans.  Seriously....

 

For the kickdown, you can search the junkyards for a small block 4 bbl kickdown linkage and throttle cable bracket, the shop could have modified the one you have (it's possible with some cutting/fabbing) or go with an aftermarket cable like Lokar. 
A search on this site for Lokar should turn up some threads and pictures of other folks on here that have one of the Lokar cables.

 

Thanks guys for all the feedback.  Looks like I'll be doing more work to this thing.  Real bummer, I was looking forward to a trail run next month, but I'll need to come up with some cash to get the Holley 470 first.  Anyone interested in a  gently used 670?  HAHAHA!

 

Also agree the carb is too big, further, by choosing the T/A carb, you will gain off-road ability but you will lose on-road ability. T/A's lack high speed air bleeds which make it run poorly at a moderate to high cruise speed.

Another commonly overlooked thing is an adapter for running a squarebore carb on a spreadbore manifold. If you don't have one, you could have an air leak. Edelbrock sells a simple one for about $12.

 

The carb wasn't a single barrel. It was a 2 barrel.

Aftermarket carbs aren't ever set right for a mostly stock MoPar engine. It's going to need to be adjusted no matter what it is. Too big/too small is going to show an extremely small portion of the time, since it isn't outlandish you can make it work. Poor adjustment is going to be a problem all the time though, no matter what size it is.

What'd you do for a kickdown?

A Holley carb shouldn't need an adapter for a Performer. I usually don't run them- and use vacuum accessories on everything.

For a true dual purpose vehicle, close to that 600 range isn't a bad place to be on a 318. 650's the wrong side of that for a heavy trail rig, but if you get it running better to where it won't stall where your old carb did and has better power down the road, that'd be a good place to be. It's what you've got so it's worth trying.