just replaced tranny, still has problems getting into gear

ok.. i have an '86 delta 88 royale.. i was expieriencing tranny slippage and grind-age.. after it got to the point where i could only drive in 1st gear, i decided to replace the tranny.. it no longer slips, but it does have a hard time getting into 2nd.. basically slow acceleration.. im going into the shop today to get a tune up, fluid flush and change, new oil and air filters... any other suggestions?? any information would be greatly appreciated

also... i had problems with the car just stalling for no apparent reason.. its happened while at a dead stop at a traffic light and even going 60 down the freeway... im a big noob.. need help.. anyone who posts possible solutions, much appreciated..