IDLE ERRATIC Questions

I Have A 93 Gmc 1500 4x4 That Recently Had Some Front End Suspension Damage And Was Eating Away Tires So I Let Sit For Winter. Weather...

Very Poor/hesitant When Acceleration From Complete Stop, Fluctuating Up And Down Rpm While Driving Highway Speeds Of 70+ Mph, Reduced Power...

Idle Goes Up And Down. You Feel It On The Padle Also

I Pulled Out A 5.9 And Replaced It With A 5.2. Now It Doesn't Want To Idle It Misses And Revs Up And Down. But When I Put It In Reverse It...