Well, I just swapped an 85 2.8 with the powermax 2030 cam, 1.52 roller rockers, and a cloyes chain in place of an 89 2.8. It seems that generally I'll run a tad rich, but some times when I start my car and hit the gas it'll bog down for a little while and it'll idle bad, every once in a while it'll kill itself right after I start it up. Other times however, the engine runs perfect.
Is my computer trying to adjust to this still or is it something else?
I am thinking I need to put in a new O2 sensor.
Although I don't hear rattling or smell sulfer, I think I should replace my cat since the old engine dumped massive amounts of Hc's and maybe unburnt gas into it
Timing is set at 10* btdc, but I am going to recheck that.
I haven't done anything with my EGR valve maybe I need a new one of those?

 

Is your computer throwing any codes? I'm just taking a wild guess, but it sounds like a MAF sensor problem. I don't know if you can get it tested, but if you can, you might want to consider that. Wait and see what others have to say about my idea before taking my advice.

 

nope no codes....and I just replaced my MAF so that better not be a problem

 

Have you gone over the tuneup parts (or has it been a while since a tuneup)? Checked fuel pressure? Did you use the throttle body from your original motor? If you used the TB from the '85, the TPS might've been way outta whack- or, if you never adjusted your '89's TPS, it might be outta spec too. Any vacuum leaks (from cracked lines)? If it was the EGR I'd think that the car would run fine until you were driving above 40 mph with a light throttle and the engine warmed up (when EGR turns on), and soon as you'd slow down, you'd stall (EGR would be "sticking" and wouldn't release, causing the car to stall until the whole engine cooled down again and the EGR pops back out).

 

all the tune up parts except the pcv valve and distrib cap have been replaced. The cap looked super clean though. The TB is from the 89, but I never did adjust the TPS on it, I've been meaning to though
fuel pressure is perfect
vaccuum is steady somewhere around 15 psi ( don't remember the real number)