Ok as some of you know i'm after a Stage 3 head (ported/polished, big valves, bronze guides, 3 angle Valve Seats, etc..), I emailed a few places regarding headwork spec and prices, and i've had some conflicting information!

Ian Howell from Area 6/Fiesta Frenzy said:

"The inlet port is too big, and the exh valve is too small.
Flattening the guides and modifying the seats will give you significant gain without doing actual porting work"

David Baker from Puma Race Engines says:

"The CVH responds very well to big inlet valves, The exhaust valves are actually far too big as standard Under no circumstances fit larger exhaust valves and any tuning firm that does this can be safely avoided as they have no clue how to modify this engine properly"

Andy weston from Cylinder Head Developments says:

"my ultimate big valve fully ported and flowed RS Turbo head has 43mm inlet and 38mm exhaust and are stainless steel"
So is increasing both inlet and exhaust sizes!

It was always my belief that the inlet side of the CVH head was most restrictive and not the exhaust, but Ian Howell has a good reputation and so i'm confused!

Does anyone have any opinions/experience regarding this as i want to get my head worked corectly!!

Cheers!