Actually I think mine were more like 230/213. If your carefull, and know what your doing somewhat, I think you could make decent improvements at home. You just have to understand you don't want to remove much from the runners. They're plenty big. Just smooth the surface a little. Most of the improvement will be in blending the valve guides and a good valve job.
If you're serious about getting the most out of them send them to TEA or one of the other companies who have shown some success with porting them. Starting with PI castings is a very good idea, but a few guys have proven that an earlier head can be made to flow pretty well if you know what you're doing.


David