Right I've just had it confirmed that I've got 13mm valve guides, so now for the next stage of the head build - ordering the parts.
Amongst the rest of the head stuff I'm strongly leaning towards the +1mm inlet (34mm), and exhaust (30mm) highflow valves - still with the 7mm stem though - the 7mm stem (although waisted) will maintain strength and give negligable power loss over the 5mm race varity.
The +1 valves will be accompanied by the valve seats being reamed out to give the bigger opening (SBD & Swindon have confirmed they'll run on the standard size seats).
And finally Henryk of V-Tuning is ready to go with a full on head job (inc. inlet manifold).
The question is: I've been told by SBD and Swindon that I will lose a little tourque low down but gain it back up the top. Do you guys reckon this is an exceptable trade off considering it will be a road car, it'll be running hydrahlic cam profiles, and rev to 8k at the most.
Also consider my engine build will include 100bhp NOS at the end of the day.
Would you go for the bigger valves if this was you?
NOTE: for those who don't know I've got TB's, 88 Omegas, Steel rods, lightened crank & flywheel, SBD 'bigboy' exhaust, electrical PAS pump