balance 440 six pack

[morpower]

?Hi guys. New member here. My dillema--I have a 1971 440ci hp2. After getting it back from the machine shop getting a .020 bore installing the 292 509 mp camshaft i obtained a ATI torque converter which is with a tape measure 10 3|4 in across(Hemi converter?) and had 100 grams of weight added to the converter for balancing. My ??? is--- I installed engine today, the converter mounting bolt hole pattern is smaller than the flex plate bolt pattern. I just ordered a B&M flex plate from Summit Magazine part number BMM-10230. They offer another flex plate BMM-10237 for a 71-up cast crank externally balanced flex plate. They both are drilled for what they call a 10 1/2 and 11 1/8 converters. since I have a converter with weights on it do I need the flex plate with the half moon cut out of it ? the one with the weight on it? or a standard forged crank flex plate that will fit the 10 1/2 in converter. Summit says I need the flex plate for a forged motor because the converter has the weights on it. Is this true???

[Brian Mills]

I don't know about all of this stuff, but I do know that you need to identify your crank as cast or forged. Then make absolutly sure the flex plate and converter are for the same type of crank. The flex plates and converters will interchange as far as bolting to each other, but, if you mix match the bolt ons, trouble with starter engagement can become a problem. I helped a fellow this past winter with a big block, near as I can see from reading mopar literature, one of these cranks is actually a little longer than the other, from the rear main to the flex flange that is. Some change was done to the flex plate and tourque mount to compensate for this at time of change from forged to cast cranks.LOL

[Christopher]

The 440+6 has a forged crank from the factory,but has a balanced converter due to the different connecting rods.(they are a lot beefier)First thing I'd do is call ATI and get a flexplate from them,but the plain forged plate without balance weights is what you need.

[morpower]

thanks guys christopher was right. its a forged crank. according to the m.p. engine book the rods are the reason theres a different harmonic balancer& weighted convertor. the engine came in pieces.the guy had it in boxes.he had boxes & boxes of big block parts under the trunk of (3) challangers & 1 cuda all big block cars so he wasn't sure if i got the right flexplate.thanks again !!!!