OK well first things first. I have a sohc zc that I am getting ready to swap a Y8 head and maybe some pm3 pistons. The thing I wanted to get some input on is:
Will I be alright to run this set up without getting the crank and everything rebalanced after I swap the pistons??
I know it's best to get it done but I'm on a SMALL budget and the engine is going in a daily driver that will never see 8K rpm (staying with stock rev limit).

 

What makes you think you will need to get it balanced just by installing some pistons and a different head? If you're leaving it at stock redline, why would you balance the crank? Honestly, I would do some more research on engine internals and how they work before working on them. Not trying to be a dick, but it will help answer most of your questions.

 

I am by no means a master tech but I have rebuilt 1 or 2 D16 and I'm completely capable of swapping piston. Only reason I asked is because the guy that machined my Y8 head said I should get it all rebalanced but I think he was just trying to get more money out of me .

 

Unless you had some kind of internal engine falure it's not necessary.