well when it comes to the price of porting and polishing a cylinder head it really depends on how much you wanna increase the size of the valves, or how much power your looking to get out of the job. porting and polishing goes by three different stages, street port which is a slight bore of the valve ports, strip port which as we all know is for drag racing and is a big power gain, and the competition port which would not be needed in a gsr head. as for a place to go this website gives you a listing of every machine shop in new york. http://www.crankshaftco.com/engine-repair-directory/newyork.html