I wouldnt spend the 350-400 dollars for 1.6 rockers and springs until I was a long long way down the road with traction and drivetrain mods. You dont need a bigger throttle body I have helped with cars trapping up to 117mph with a dead stock tb and seen no change when a 58mm was swapped in its place if there is an improvement on a stock car its probably because it leaned out the air fuel ratio since stock it is pretty rich.

You're not wanting to spend alot of money, so just stick to things that make a drastic difference. Maybe i'm a bit numb but I cant really feel 10-15hp.

 

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