I want to know if they are worth putting on a d16y8 engine?

 

Unless your going to have it tuned/adjusted on a dyno, no.

 

Definitely. do you know how much of a gain i would get?

 

No I don't. Probably not enough to be worth the time and money wasted putting a cam gear on a stock single cam engine.

Also you will soon find "How much hp" "Whats the best header" "Whats cam(s) are best" type of threads will get quickly locked and deleted.

 

on a d series? ehhh single cams are meant for mpg, not performance...