The "L" engines are the torque engines designed for lower rpm than the standard or "LX" engines. His website is very outdated so you'd have to email him for specific models. On the aluminum AAC liners, he will fit a new piston. A worn out brass ABC liner usually needs to be replaced. Aluminum liners don't bellmouth like brass liners do it seems so I'd assume that's why a new piston can be fitted to a used liner. The chrome rarely wears, it's the piston that wears and I'd attribute that to lack of lubrication.

Another thing that's nice and you don't see very often is all of Jett's engines are tapered bore ABC or AAC. Even the 1.20 they used to make came AAC.