If he will replace the old ball with a 10-11 lb. ball, this is a "whole new ball game". I don't know of one manufacturer, off the top of my head, who uses the same core in 10/11 lbs, as they do in 14/15/16 lb. balls. There may be one in a some low line balls.

I think your friend should buy a used ball from the pro shop to see what weight will serve him best. People can use some fairly heavy balls that are fitted properly to their hand. Women are especially surprised how much weight they handle when going from alley or badly drilled balls to properly fitted ones.

Once that's decided, then he can worry about the type of ball.

Jeff,

I think he said that the old Heat he had was 12-13# and he is currently using 11#.  I will check Monday.

I already mentioned to him that the cores would not be the same.

One key is the Match Up Hybrid has the exact same coverstock, which is the biggest pertinent factor.