In Autograss class 2 rule book, it allows the Cylinder head to be skimmed to 110.5 MM minimum thickness, then a three angle valve job, but no cutting of the valve throat, there s a figure of 30- MM dia .mentioned for the inlet throat. after that its all standard , Two Camshaft s are allowed T1 and T5 ,Choosing the the best head helps* , the inlet and exhaust manifold s are free as is the carburettor and air filter .
* Bob may share this information. (Y)
