I would take the vforce because they are only two strokes. Boyson has been working on their four stroke side because the stupid environmentalist had all the manufactures stop making two strokes. So I would use something made by someone who knows two strokes
Head OR cylinder??
And how do you figure that?, I've got the LA Sleave kit on my Blaster in the original cylinder and it's got over 100 hrs on it now!?