Originally posted by Top Gun 777
It is depend how much you will put under sleeve shims. great amount will kill bottom end completely-engine will be for speed only ( realy fast on the end of long straight) but it will be realy slow on bottom end. I have tryed to raise sleeve on 21 Nova by 0.5 mm ( all timing raised by 11.5 degree)-it was no good!!!!!! Don't go there, it will be very high speed engine with no bottom end at all.
Yes.
Before you mod your engine,you need to think WHAT is not enough or WHAT is too much. If you don't have any idea,don't take risk. You can get the same result on gearing and pipe tuning. When it is not enough to you,then just think about mod it.