From the "TFTLCD-Library-master" directory on my PC:
// Shield pin usage:
// LCD Data Bit : 7 6 5 4 3 2 1 0
// Digital pin #: 7 6 13 4 11 10 9 8
// Uno port/pin : PD7 PD6 PB5 PD4 PB3 PB2 PB1 PB0
// Mega port/pin: PH4 PH3 PB7 PG5 PB5 PB4 PH6 PH5
// Leo port/pin : PE6 PD7 PC7 PD4 PB7 PB6 PB5 PB4
// Due port/pin : PC23 PC24 PB27 PC26 PD7 PC29 PC21 PC22
// Breakout pin usage:
// LCD Data Bit : 7 6 5 4 3 2 1 0
// Uno dig. pin : 7 6 5 4 3 2 9 8
// Uno port/pin : PD7 PD6 PD5 PD4 PD3 PD2 PB1 PB0
// Mega dig. pin: 29 28 27 26 25 24 23 22
// Mega port/pin: PA7 PA6 PA5 PA4 PA3 PA2 PA1 PA0 (one contiguous PORT)
// Leo dig. pin : 7 6 5 4 3 2 9 8
// Leo port/pin : PE6 PD7 PC6 PD4 PD0 PD1 PB5 PB4
// Due dig. pin : 40 39 38 37 36 35 34 33
// Due port/pin : PC8 PC7 PC6 PC5 PC4 PC3 PC2 PC1 (one contiguous PORT. -ish…)
It looks as if it supports 2561 as well as 2560. If you select the "Breakout" the data bus is on PORTA. If you select the "Shield" it will use the "Adafruit shield" wiring.
We have no idea what "cheap 2.8" TFT display" you are using. The Blue 2.8" Mcufriend shields have the data bus in the "Breakout" pattern.
Seriously, life is much easier when you provide accurate links to the actual hardware and software you want to use. If you provide a schematic of your special hardware, you could get a tailored reply.
David.