the truck is an 88 but i got the motor a couple years ago and it only has 15k on it. i did leave my o2 hanging im going to go drill out the hole in the header right now and hook it up and see if that does it. the tube to the smog pump is just open. do i need to block it off?
where do you plan on putting the o2 sensor? My downey header has a spot for the o2 sensor and it picks up off of cylinders 3&4 i think you want you want your o2 sensor to at least pick up 2 of the cylinders not sure if it would matter a whole lot though. Yes i would block that hose off you dont want it sucking outside air and dirt.