missing,knocking..no power 85 350 and my trans

[dpools2002]

hey guys...i have a 85 gmc with a 350 in it..it6's messed up bad...it really wants to run good i think but?...1st..i need help with the vacuum lines.i have the drawings for it ..but if you don't know what a efe or a delay valve looks like it doesn't do any good.right...it start rights up runs preety well till it gets hot..then so-so.....it never dies on me .........just when i try to go to fast to soon .it knocks and pings bad............plus when i'm going ..it shifts kinda hard into 2nd gear..........if i let off the gas i'll shift fine........but then it won't shift into 3 till about 45 mph ..and thats when i let off the gas...........and when i give it gas again.it downshifts and intill about 55 mph then it'll stay in 3rd.......but it'll just keep down shafting back into 2 if i give it gas below 50-55 mph...........anybody help me on this..........i justy got the van and the vac line coming from the trans goes straght to the big vac suckon on the back of the intake?......aghain sorry if this might not make any sence to anybody.if not i'll try to word it better............i just know it's costing me a arm and a leg to do my work around this town.....thanks