I plan on doing cams and hc piston in stock bore within the next year. Just wondering what the benifits of a shim under bucket setup has over the stock. When is it required to go with this.

 

From my understaing you want the shim under bucket as soon as you are running any high rpm's Without it there is a chance the shims can slip out under a big rpm pull. Never a good thing to have loose parts floating around.

 

With the shims under the bucket you remove the risk of having a broken shim fall into your valvetrain where bad things are bound to happen. The heavy duty springs that come with the shim under kit also help in minimizing valve float. Not all cams require shim under kits but if you want to safely rev to 8500+RPM I would recommend you pick up a set. Cheap insurance when you consider the cost/time associated with engine repairs from the scenarios I listed above.

 

if you aren't reving over 8000 you should be ok, but make sure you stay on top of your valve clearances.