I got the 4aze block and it apparently needed enginge work. the shop is boring it to 81.5 mm, but they want me to buy some pistons before they do it. I am going to buy some wiseko forged pistons but I noticed it gives the option to increase the diameter of the pins...... should I stay at the 20mm size or go larger?. I plan on keeping my old stock rods. Also , while I am at it, the same shop is doing the headwork (standard rebuild), but perhaps I should buy the hks racing springs as well.