Internal balance

[lampy]

I have read a few threads saying the 2.8 with a 2 piece rear main seal is externaly balanced and the one piece rear main seal engines are internaly balanced. The family tree says 84 is the switch over year to the larger crank and one piece rear main no mention about int. or ext balance.87 RWD hit or miss for internal balance, 88 is the year they switched to internal balance, so are these threads wrong or is the family tree wrong? My question is does a one piece rear main seal mean the eng. is internaly balanced or do I need to pull the pan to look for the wheel in the center of the crank?

[geoffinbc]

I was wrong. One piece seal indicates large journals. Not the balance.

To ID the crank you have to check the reluctor wheel. Or if you cannot see the crank in the engine then knowing the year of the engine or seeing the flywheel/flexplate is the only other way to tell. You cannot trust 87 RWD vehicles since they are hit or miss.