I am restoring a 70 Challenger R/T 440 U Code with an Oct 21, 1969 build date. The original engine is long gone. I found a 440 HP block with an 8/12/69 assembly date. The parts manual, 440 Source, Galen's reference, and even the ICCA reference book says F440 HP's came with six pack rods, dampers and torque converters. I have spoken with several reputable mopar engine builder who say that mother Mopar did not put the six pack internals in the 440 HP until late in the 70 model year - any truth to that? I have accumulated the six pack rods, damper and converter. I also bought a new Eagle forged crank because I figured it would be easier to balance this non matching rotating assembly starting with a virgin crank rather than one that's already been cut or filled. I have spoken with several engine shops - they all have different opinions on how to externally balance this engine considering the offset weights on the torques converter. How does one balance this assembly? Can anyone point me toward a good Mopar engine builder that has a clue in the NJ or Phili area?  

was your  car a 6 pack? u code a 440 car no? if it aint an original 6 pac car then dump the 6pac rods and use eagle aftermarket rods instead .in order to internal balance you would need to add mallory metal.not cheap. can the 6 pac rods unless they are magnafluxed,and checked for stress crack.them 6 pac rods seen a lotta cycles and abuse and weigh a ton making your internals heavier.I dont know what your intentions are or if your cars an original 6 pac car. I would can the external balance altogether. to external balance a negative balance engine you will need the external damper used for the 6 pac rods,you will also need the specially balanced flywheel and or the external balance converter .to identify it you will see weight added to each side of the drain plug and theres plenty of new ones to go around.heck, they used 6 pac rods in 74,anyhow this is all thats needed assuming you have the right balancer but a lil off balance wont be felt.you can still internally balance your pistons with pins in them and balance the rods,index the crank and such so there it is basically imo  I like going fast and the lighter the internals the better for me, take care ps balance the driveshaft too, not for the external balance as it dont matter but for a smooth ride.  

Thanks - U Code is a 440 HP four barrel, 375 horsepower. The references say the internals are same between the V Code 6 Pack and the U Code except for the cam, distributer, intake and carbs. I agree it would be a lot easier if I went with the Eagle or Cat rods, internal balance and a neutral balance conveter and balancer. But I am trying to do the engine correctly as it would have left Motor City in '69.  

then just find a good set of the lighter weight factory 440 rods, if you decide doing it your way the v code used a piston valve relief notches as only the 6 pack engines used them .I say your references are crap, good luck using 40 year old parts. no offense meant but why not use the best parts internally its still a u code and if anything I would pay more for it then a beater with 20 million cycles on it,heavy old rods and a 40 year old balancer on it.  

just tryin to help, long as its a u code and matches who cares? go with the best internals, new, imo  

if its an e86 code I think your wrong and galen govier is a knucklehead,heh  

I got a bunch of 6 pack rods from cars and motorhomes if ya need a few spares  

I hear you, sure would be convenient and better to use new parts and not worry about being as authentic as I can. At this point the six pack balancer, rods and torque converter were all professionally rebuilt so I am not worried about the parts failing. The rods were magnafluxed and ARP fasteners used. I am still not sure  how to balance the thing. Someone said use a six pack flywheel and gave me directions how to drill out a neutral balance flywheel to be weighted as the six pack flywheel. Sounds reasonable, still a pain.  

7 posts up should answer your same question again. no offense but read it.its the converter or the flywheel,take your pick, I would use the converter personally.  

converter for a 440 6 pack part # P5249326 from M.P. call jegs ,they sell M.P brand name, application 440 6 barrel, and also works on the 440 4 barrel with heavy rods and steel crank. the 440 heavy rod and 440 6 pack got their balance from the torque converter not the flexplate, only cast crank external balance 440s used the weighted flexplate from what im reading, take care  

you will need the correct external harmonic balancer also  

im not a galen govier kinda guy but the question wasnt to dang hard to answer on my own hahaha, take care double threader  

now buy the 6 pack pistons with the reliefs and its a 6 pack engine.  

a u code will never be a real deal 6 pack engine as its not a v code and would have had the 6 pack only v code piston reliefs. who won?  

Not trying to make it something it isn't. Just trying to have a correct E86.