Action Plus, 360, or...?

Ted Carlson said
The action plus is the only one with the proper bolt configuration for a roller motor heads. LA style are perpendicular to the head while the later style are verticle. You would have to drill the intake for LA heads to fit.

His is a 1990 model engine. That's an LA roller engine. Non Magnum. It has standard LA cylinder heads.

At least, that's what I have gathered.