need info on a block

[Badd Azz TTA]

has a casting number of 25500004
i believe it is a stage 2 block,not sure though.
asking for a friend

thanks

 

[Geoff87]

From GnTtype.org.....

Stage I 3.8 Off Center Block (virgin) - Casting number 25500012
Stage I 3.8 Off Center Block (finished) - Casting number 25500012
Stage I 4.1 Off Center Block - Casting number 25500016
Stage I 4.1 Off Center Block with O rings - Casting number 25500016
Stage II 3.8 Off Center Block - Casting number 25500012
Stage II 4.1 Off Center Block - Casting number 25500017
Stage II 4.1 On Center Block - Casting number 25500153
Stage II 4.1 On Center Block - Casting number 25500153 (modified)
Stage II 4.1 Aluminum Block - Casting number ?


Not sure what block that is....

 

[turbofish38]

I found a reference in V-6 Performance by Pat Ganahl to part number 25500003. "For extreme or sustained racing you would be much wiser to start with one of Buick's heavy-duty blocks, none of which has been offered in production vehicles. The first(part number 25500003) was produced in a limited run of approximately 200 units in 1979." On GM parts a lot of times the casting number is one digit off from the part number. Also Stage blocks have a Power 6 logo cast into them, does yours? BTW V-6 Performance was published in 1982.

Eric Fisher