OK, long story short. GTX is a dog, punch it from a stop and it will just chirp the tires. I can't feel a hesitate or bog it just doesn't have any power (been this way for years).

Here is what it has:

440 .030 over
forged six pack replacement pistons
old (20 years old) 284/484 cam
ported 906's
Edelbrock RPM manifold w/Holley 750 Advenger carb
~18 inital timing, ~34 total
727 w/340 converter
3.55 suregrip.

I know the cam, car weight, converter, and rear end aren't matched the best but it can't even turn over the tires.

Before I painted the car I could get it to break the tires loose through the gears and only thing I changed was the converter. I took out a stock looking converter and replaced it with the 340 converter thinking it would help.

So, is my setup so miss-matched that I'm screwed or do I just need to go out and buy another converter? I would think that this combo should be able to shred the tires with a stock converter????

Did you feed it breakfast?

I wish it was that simple!!

It sounds GREAT but has no teeth. My small block Demon will blow it off the road!!!

How quick does it rev up when it's in neutral? And does it have six pack rods also?

I learned many years ago to put a decent stall converter behind even the 474 mopar cam on a 440 car. I have not bought one since 1978 but a B&M super holeshot turned the 440 cuda into a tire shredder. I currently have a 500" low deck with a PTC 9.5 and it rocks.

Did u degree the cam.also 484 likes a 2500 stall

If you have the old converter still put it back in
I don't and won't use any of the newer Mopar Purple Shaft street Hemi grinds, especially the famous 284 street hemi grinds

Seems to be fine in neutral.

I have a PTC in the Demon and it rocks!!! I think it flashes around 3700 but I don't want that for the GTX, I'm looking for something a little more streetable if possible.

I didn't build the engine, it was build 20+ years ago and has about 5000 miles on it.

I looked up the part number for the 284/484 cam it in and it's the old one. He gave me a pile of receipts two inches thick for the motor/trans.

I know a converter can really wake up an engine but shouldn't an engine like this be able to put some hurt on the rear tires even with a stock converter?

I would get a cranking compression number & maybe a leakdown also

Maybe the '340 converter' isn't really a 340 converter, or it's bound up inside for some reason. If it started doing this right after installing it, I'd say it's the converter. If you don't have the old one, maybe borrow one from somebody before buying a new one, if you don't mind removing the trans a few times.

How tall are the rear tires? They look tall. Was the cam degreed in? It could be retarded. What type of fan on the engine, solid mount or clutch fan? is the carb a vac secondary or mechanical? What ignition system? How tight are the engine clearances? I agree that your 484 cam likes a converter.

The 484 is not a hemi grind cam. The 474 is and I don't think it works very well at all.

The tires are 28" (275/60/15) I don't about the clearances, I didn't put the engine together. I don't know that the cam is degreed either.

I have the receipt for the converter and it shows 7642 and I believe the 764 is the 340 converter.

So it sounds like my assumption about a mild 440 being able to smoke the tires with any converter is BS.

I'd make sure it's getting full throttle first, and if it is.......I'd see if I could borrow a different carb.
I'd be looking for a 750DP if it were me.

As long as the converter isn't broken/defective, and assuming there was a good carb on it, that combo should run pretty good.

I second the thought of doing a compression test on a least a couple cylinders, just so you know where it's at.

I took off a 750 DP because I was told the mechanical secondaries were compounding my problem. Unfortunately the carb sold with my barracuda a couple of years ago.

I'll have to compression test.

OK, I made one mistake. I looked up the part number for the pistons (2286P) and that shows a stock replacement piston the six-pack piston so my compression is lower. BUT, like I said, when I first got the car it would shred the tires with this same engine...

Also, I just remembered that I had to back off the timing due to bad predetonation during hard throttle. Still has that problem a little bit. Compression ratio should be good...