What is the difference between that and a 340 external balance flexplate? Sincere question here, I don't know. I thought external balance was external balance...? Is it the amount of weight distribution, or....? So, it's important to get a 340-specific one and not use a 360 one? (Thank goodness I'll probably never build a 904 since I have 3 small block 727's already, but I still want to know!)
Thanks