I've seen an old post from 2009 about this, just want an update.

Valves have gone a bit funny on my 29. Looking to get a new head as it'll cost less. This forum seemed to say the 23 head would fit without trouble. A fireblade forum mentioned changing oil bores and having oil leaks as the gaskets are different. Just looking for a bit of advice/answer as to whether it'll work easily before I go and buy one. If not I'll be looking for a 29 head very soon.

Thanks in advance.

How did you go? For the record...

Very easy to fit a 23 head to a 29.

Use the 29 head gasket and cams. Line the head and block up, you will see that the oil gallery (i think at the back of the block) does not line up to the one in the head. Grab a hand drill and drill a 45 degree hole into the head to line up the holes. Use a drill bit the same size as the gallery.

It's been so long I don't have any pictures of this, nor remember the sizes sorry. But it's only a few minutes work.

Managed to source an NC29 Head for £50 fortunately.

now its just getting the bike ready to race!

I want to do the reverse? Put a nc29, or later model 88-90 head on a 86nc23 with adjustable rockers will this work?