You can get a set of .015 shims from Goodson http://www.goodson.com/store/template/product_detail.php?IID=3499 I have a set I'll sell you for $10 bucks brand new never used.

But I don't think this is positively your problem. You have listed problems that are still very confusing. Your engine needs to be properly diagnosed. Rule out all other problems and or causes before you start shimming the tower.

Maybe you have the wrong valve springs? I don't know. Where in Ontario are you? There is a very strong Ontario Z club that could probably help you out.

Im from Kingston.

I managed to get ahold of a couple engine builders and machinests that were familiar with the L24 engine. Their advice was that whoever rebuilt the head messed up and should have shimmed the cam towers.

I don't understand how they can say that - without first knowing how much has been milled off the head - or what the current thickness of the head is (same thing).

I agree with Ed... if the cam towers were sitting too low, relative to the crank center... all valves would be effected.... and you'd have problems with the tension or lack thereof on the timing chain...

Like Phred suggested - it's time to pull the head off and put in on the bench, so you can check everything.

Also - you'd have to supply far more details about what all work was done on the head and valve train...

There are two lengths of valve stems.... as I recall... and long ago I did see a problem caused by the Parts Dept. getting them mixed... the result was the machine shop put them in and a couple of the valves had almost 0 adjustment.. I believe that happened partly because 280Z valves were ordered for install in an E-88 head...

I really can't see it being a problem with the height of the cam towers...

FWIW,

Carl B.