yes port and polish done correctly will definitely improve performance...
price depending on who is doing it... there is no fixed price for port and polish job...
u can try nastyportflow in usj 1, behind summit.... they have some high precision tools there.... its not like u can try n error when it cmoes to pnp ur car.....
If you in jb can try xh racing,call0197853245.
I did my 6a12 v6 pnp together with 3angle and skim head at xh racing ,jb.price affordable.definately increase hp but need to adjust valve timing.
Again from my tuning and set up for 1.6L 4age NA block can push up 499whp at RWD AE86 body.Amazing runing with low boost at calder park drag way in Australia,my buddy happy with 10.02sc 1/4mile.Look what we do at the...