I went the Zetec route in the end. My old CVH had a big valve head, ported and polished, skimmed, high lift cam, bored out, blah blah blah.....


I just lifted it out and dropped the 2 litre Zetec in, bolted on the bike carbs and away i went! Very little wiring involved and the performance increase from a standard Zetec over the tuned CVH is vast