Truck is an indoor truck and dosent get outside,it does have the up high intake where air is drawn into air cleaner thru the OHG.....it has a new distributor on it so don't know if side play is an issue....am going to ask if when the reman head was installed if it came with the cam or if the old cam is in it??? Possible cam issue......am leaning also towards the crappy model J I put on a while back being the issue....had that with one other customer recently and a COBRA cleared it right up.