Bugga. Beat me to it😄You only need to make manifold bolt holes little bigger and they will fit to 1098 heads. Done that been there. Buy it if it's good deal. No problems to fit it then.
Yep, holes need to be made little oval. 1198 ports are little bigger so from 1098 head to 1198 exhaust it's good. Some aftermarket performance exhaust are made so that there is that step. It keeps exhaust gasses coming back to exhaust port from exhaust. Or something like that..So just the flange holes need to be opened up? The ports will match up fine then