1st to 2nd slipping/quick

Trying to get some things sorted out before winter.Had my 904 rebuilt with a tf-2 shift kit also.Problem is under full throttle it shifts into second almost right away and softly .If I try and shift it manually it just slides into gear.Under light throttle it shifts harder and later than it does under full.2nd to 3rd seems nice and firm.I've played with the kick down and it doesn't affect the 1st to 2nd shift any but just delays 2nd to 3rd.If it matter I'm using a Lokar cable kick down.Have been told it could need the 2nd gear band adjusted,but I'm thinking it could be how the shift kit was installed/valve body.Talked to the shop who rebuilt it,but he wants more$ to look at it,and I don't have alot of faith in him.To his defense it has been over a year and it's my fault for not getting it to him sooner.by the way does anyone know of any good shops within a 100 mi radius of youngstown,ohio? Rossler racing transmissions is near me but isn't taking in any more work at this time and specializes in GM trannies.