whats up guys?my 1989 iroc 5.7 tpi starts up ok and at idle it sounds really good,but when you try to floor it it will accelerate slowly in park or in gear.I just finished putting it back together after 3 months. i changed the push rods and gaskets on the intake manifold.(it was leaking oil from the back part)Im not sure the timming is exact.would that cause it? Anything would help thanks alot guys!

 

That would definately be a factor. Was the throttle body coated with carbon? That would also affect it.

 

Try cleaning the throttle of the carbon and definetly have the timing checked because that would cause a lag.