All heads from 194,230,250 292 will interchange. Just the 194 has the smallest CC chamber. Their are a few 194 heads that had close to the same CCs as the others, but most where small CCs. YES the lump bolt can be cut off with a dremel size disk. Yes the heads did have to different size plugs 5/8s and 11/16?? . One has a tappered seat the other used a washer to seat.
If they put PC seals in the head you will have to replace them if you remove the valves.
Sorry I can't help you on the exhaust. mainly because i don't use them I build my own headers.
God doesn't like ugly.
