OP asked if KB399 pistons will work for his build.
One person in particular tends to get snarky with people when his opinions and attitudes do not align with his. I do not abide that kind of BS and bullies.
Considering nobody stepped up that has used these pistons, I checked the manufacturer and Summit web sites, and both indicate they should work OK. I related that for the OP and got jumped on for that, at which I defend my actions or statements.