Will increase compression by .5???
Yes it will work- The difference between the gaskets are the fact that the ZX3 gaskets is a 2 layer steel compression gasket vs a 4 layer one on the svt.
I would go for the head gasket first- Milling the head limits what you can do later with the head.
As for clearances they are fine. The engine is an interference engine. AS LONG AS your timing is CORRECT you shouldn't have to worry too much about it. Im using cams with VERY HIGH lift and have not had any issues aside from timing.
