i was wondering if anyone has done this already use their stock valve train and upgraded and got a difference without a tune i wana get skunk2 stage 1 cams is it going to damage anything im just usuing it for street is there any good in this or should i just leave the stock GSR cams for it another thing is i have Nippon racing pistons in the block with eagle rods but the head is stock is it worth to put the S2 cams or just leave the GSR cams??

 

They're basically ITR cams arguably a waste vs the tuner 2's... so you may as well get tuner 2's in which case you do need something like super-tech/BC or skunks own valvetrain, yes a proper tune is required.