A518 shift points

[THMPN73]

Ive got a A518 in my 73 charger (which I love for the highways...just the flip of a switch and you lose 800 rpm) and I recently put a B&M stage II shift kit in it and was hoping for a harder shift and the maximum that i can get it to shift at is 4300 rpm with the kick down adjusted full.
so trying to see if i could get it to shift at a higher rpm like 5200 or so i removed the linkage and tested it with the kickdown lever tied back into the WOT position and still it wouldnt exceed 4300 unless i manually shift it.
but while i was doin this i noticed that if I would creep up to 4300 rpm at 1/4 throttle if would shift very hard(the way i want it)..but when i gave her the juice it would shift much less snappy
does anyone know why its not jamming into gear..is it slipping?
and also is it possible to increase the shift point somehow or was this tranny just not designed for this kind of application?

[John_Kunkel]

I wasn't aware that B&M made kits for the 518, what's the part number of the kit?

Once the upshift limit of the trans is reached, the only way to raise the shift speed is with a governor kit. Check with A&A as to whether their governor kits will work with the 518.

http://www.aandatrans.com/OnlineCatalog/tabid/53/Default.aspx

[THMPN73]

Its a B&M transpak kit part number BMM-10227
Im not really very impressed with it for the money and time it took