Best options: If you gonna turn 8000 rpm and above you can go Nickasil on AL but otherwise it is just a total waste of money. I been using iron sleeves for years now and most folks do unless it is raced professionally where winning is more important than expense.. Iron sleeves are easy to re bore to larger size or replace a sleeve.. I sometimes just bore a block just enough to clean up a true cyl in the aluminum and have James make me a sleeve to fit it instead of going a .020 or larger over size and it leaves a lot more room to repair the engine again later.. Advance Sleeve Corp can also do that but it takes a while to get it back.. Advanced sleeves are nicer and better quality than the LA Sleeves.. JMO..

