[dynomatt]

It's been a while and there's posts somewhere here about what I (and subsequently others I believe) have done.

Get WRX heads. Strip valves, springs, retainers and collets. Throw away buckets.

Get SVX heads. Strip valves, springs, retainers and collets and throw them all away. Keep buckets.

Install WRX parts. Cutting new valve seats, may as well install new stem seals while they're all out.

Gut buckets. I used a lathe with a cutting tip and ran it around the edge of the hydraulic base. Time will tell whether this is a suitable option, but so far, none have failed. (when you do this you will realise that the shim sits on the bucket in a less than perfect way...it works, but less than perfect). I've since found that some shim over bucket options at 33mm exist, just remember that for large lift, the shim will be too small.

Measure clearances, and order shims that sit on valve stems to obtain correct clearance.

This is all pointless if you haven't got new cams that have more than 8mm lift BTW.

M