Need some help with a few problems i havent been able to chase down

[FTC]

hello everyone im still a beginner with buicks, but anyways since i bought the car its been having a problem when i go WOT in 1st gear only, it pulls well until around the top of first 4000-4500 RPM the car starts to stumble/bog/surge im not sure what to call it, then continues to pull how it was before. i dont really know if the boost is fluctuating or not cause i always have my eye on the SM looking for knock, which leads me into my next problem. on the low end of a pull the car will run really rich like 850's and when i get to third gear it leans out fairly fast. i though it was cause i was running too much boost on pump gas but ive turned the boost down to 10-11 PSI and it still does it. i can run like 15 PSI on xylene but thats pushing it. could it be the PCV valve by any chance cause i have a fram piece in there right now thats the only thing i cna come up with right now. TIA adn appreciate all the help.

 

[donZ]

maybe valve springs, getting weak?

 

[FTC]

ok well i took care of the stumbling problem, im pretty sure it was a leaky crossover that i fixed. but im still runnign lean up top, it happens when it goes into third gear then the O2's start dropping, but through 1st and 2nd they are showing rich always over 800. the KR happens usually around 65-75 MPH, i only let it go for 1 frame then immediately get off it. i havent had a chance to pull a pulg yet but wat could it be?? bad injectors? or am i simply running too much boost for the octane, i really dont think so cause it is set very low right now ~10PSI or less.

 

[sixgun86gn]

Is fuel pressure going up proportionate to boost?What is the pressure set at with the line off?

 

[FTC]

the pressure is set at 45 PSI line off, and i cnat verify for sure that it does go up with boost but im almos certain that it does, because the regulator is new and it woudl imagine that it woudl lean out in 1st and 2nd too if it didnt.