I have a few flex plate options on my now rebuilt 4r100 and I would like some advice from you guys. The 4r100 trany I have has an aftermarket torque converter that I would definitely like to use but it is going on a 7.3 idi with the 4 stud pattern. I could buy an e4od converter and flex plate but I would rather not pay any more than I have to. So the question is can the flex plate on a late year Powerstroke bolt to a 7.3 idi allowing me to use the PD converter? Even a universal flex plate might be worth it if they make one. Also wondering if I can use the c6 flex plate I have from a 6.9 if I do have to go with a 4 stud converter. Any opinions I'm sure will be interesting.

 

The flexplates are not compatible across the powerstroke transition (crankshaft bolt pattern is different).

The flexplates within the IDI series are compatible when dealing with stock parts.

1991 and older use a cast iron flywheel with a stamped flexplate, while newer engines use a single piece plate with a balance weight, and spacer to make up for the absence of the older cast iron flywheel.

I've been told that if you use an OEM style torque converter, you are fine with either version of flywheel. However, if you use a billet front cover converter, then you might have an interference problem with the crankshaft bolts on the older style of flywheel/flexplate. I've had to deal with this problem myself.

 

I guess I will check it out with my flex plate and buy an idi converter. I saved enough money rebuilding the transmission myself that it's not a big deal. Always good advice David. Thanks.

 

would I be able to drill new holes after i welded the 4 holes up in the flex plate from my 4 stud E40D to make it work with my new 4R100 and 4R100 converter?

 

You have awakened me. Like a sleeping vampire im now awake and back on this forum haha. It’s been a long time apparently. That’s what happens when you get married and life changes.

I wouldn’t mess with drilling or doing any welding on a flex plate personally. I’m not a professional welder. That being said, I think you would run into issues such as cracking. Flywheels have a little more leeway (if they are steel or aluminum) but flex plates I wouldn’t mess with. Better to work out another plan or have a custom flex plate made $$$$