Pushrod rubber size how much to remove

[Rick Hughes]

Im slowly collecting the bits and bats to build my 2nd engine I call it my slow engine as apposed to the other the fast engine ,,hopefully with its low compression piston and standard cam and oil pump, rockers that will take a valve lifter. It will be a better type of engine for me kick over and ride as I would like .
I got a full gasket set and the pushrod rubbers are too tall
Iv read as many searched posts on here as I can but can't find
How much clearance before tightening the head down currently its 5mm my engine is a iron head vh 500 and do I do both a little or just say the top ones
How do you cut them down I have visions of hacking them with a stanley blade but my brain can't fathom a more exact way..can they be ground or sanded ? or is their a proven method

[Simon.Gardiner]

Iron head? I always just crush them down with tightening the head bolts. (Even the original Ariel ones - from my Ariel gasket sets - are much too tall).

SG