Hmmmm, I also have no cat on 1994, I also put an aftermarket alternator ( black one )& dry cell battery & the only major problem I had was the waterpump ( cause its ole & igition beside that it good, alot of aftermaket parts,lol. My 3.4 has 155,000 miles on it & its still ready to fight , LOL talk to you later

 

What plugs did you put in?

 

When you fire it up does black smoke come out of the tail pipes>