My first post...Got a 77 cutlass stock 350 olds with original carb(I think) 17057253 that still has the plastic caps on the mixture screws. The carb has done outstanding considering it usually sits for a month and has never failed to start. Never floods. The problem is it's weak at part throttle. Fine at idle, cruise and wot. Vacuum is 21 at idle, 19 or 17 at cruise depending on speed, but you have weak acceleration until 5 inches or less and then it hauls..Any ideas?...I have the book(love it!) and a rebuild kit ordeted