Head gasket size???

[chedder]

Hi Guys, need some info; have purchased a pair of 34cc heads off a 3.9, they have been ported and polished and fitted with a set of 42mm inlet / 38mm exhaust 3 angle valves and other bits of wizardry to assist the flow rates.
My block is a 3.5 and what I need to know is.....what size head gasket do I fit???? do I fit 3.5 or 3.9
Might be a bit of a 'no brainer' but want to be certain I fit the right ones for obvious reasons.
Plus, anybody know what cc the standard 3.5 heads are?

[Wedg1e]

Lots of bumf on the Rimmer Bros site as I recall...

[TVRleigh_BBWR]

Would have thought you would need a 3.5 gasket, as this will match the piston bores.