Optimizer ID

[hiredgun58]

Can I ID an Optimizer from the serial # ? Are there external ways to ID with the intake still in place?

 

[OrionThade]

If you can see the passenger side rear of the block and get the date code off it you can tell. The date code is different on the Navistar-cast blocks vs the GM-cast blocks. Also, anything newer than 2001 will be Navistar and not GM.

 

[hiredgun58]

Does "F14" over top of "506" make any sense??

 

[great white]

Quick and dirty as long as no one has played hanky panky with the valve covers:

GM 6.5's have "GM" stamped in the valve cover sheet metal, GEP Optimizers do not.

 

[fallout]

There is an extra raised portion of the casting and tapped hole by the motor mount plate that the non-optimizer blocks dont have see the pic

The above motor is mine dont have a comparison photo if someone else has one post it up.

 

[racedaymechanic]

There is an extra raised portion of the casting and tapped hole by the motor mount plate that the non-optimizer blocks dont have see the pic View attachment 30269

The above motor is mine dont have a comparison photo if someone else has one post it up.

I used that hole on mine for the passenger side ground