Budman78

iTrader: (5)

Because it's a LS6 casting. I read an article about some F-Bodies getting LS6 when GM switched vendors in 01. At least 10 percent of the V-8 cars got 12561168 casting which is the LS6 block. After reading on it says that the color of the casting is alot darker than the LS1 due to a different casting process. After getting home tonight I now know. On the back of the block are those nice cast numbers...12561168..

Vendetta

Did they actually add anything performance wise?

LS-1st-Gen

Its a stronger casting, No actual power gains, but better to build on.

Budman78

iTrader: (5)

I believe the oil passages are larger for highier rpm's and the block is beefier.

ls1_55

I have the same casting # on my '01 vette engine. Thanks for the info.

ls1_55

I forgot to ask. What is the best way to clean up the aluminum blocks?