for reference, this is what went in;
http://www.prostreetonline.com/x/darton-mid-sleeves.asp
Darton MID Sleeves
Darton pioneered modular sleeve designs and specialty ductile iron material beginning with their manufacture of top fuel sleeves in 1978. Darton sleeves excel in the harsh environment of all-out racing. Their centrifugally cast nodular composition represents the highest quality of any cast material. The unique matrix of Darton's centrifugally cast nodular iron sleeves provides unexcelled surface toughness. Darton's unique casting process provides a bore finish which, while very tough, promotes quick and total piston ring seal for the most complete combustion possible from each cylinder.
Darton now has engineered a superior solution to open-deck sleeve weakness by using a unique design which creates a solid deck of sleeve flanges held in tension, reinforcing the upper deck area and provides for in-field replacement with what they call “Modular Integrated Deck” (MID).
The Darton MID kits feature:
# Improved block integral strength
# Improved cooling
# "Wet sleeve" replace-ability
# Increased horsepower output potential
# Superior oil and compression control
# Street or strip application
# Kits can be installed by your local machine shop
# Full installation manual with every kit sale
# Superior cylinder sealing and ring wear
# Ductile iron w/130,000 psi tensile strength