Head Gasket

Hey i have an 89 civic hatch with a 1.5 D15b2. I need a new head gasket and i figured since ill have the head and everything off im gonna put a underdrive pulley on and a cam gear? Do i need different belts when putting the pulley on or do i just use the same one and is it smart to replace the timing belt if im taking it off and putting it back ok?? Thanks for any help!!!

no you wont need different belts since the only thing different is the weight of the gears. it would probly be better to change them all since youre workin on that area of the motor so you dont have to go back to it later or worry about it when youre driving.

When was the last time you did timing belt/water pump? I'd say if its been a while, nows the best time to get those replaced...if you feel you can.

no need for a cam gear with the stock cam.
underdrive pulleys cause premature wear of crank bearings as well.