The asm listing shows these instructions.

Code:
    MOVE?CT    000h, _T1CON??0
    MOVE?BB    TMR1H, _TMR1RunOn??HIGHBYTE
    MOVE?BB    TMR1L, _TMR1RunOn??LOWBYTE
    ADD?WWW    _PreLoad, _TMR1RunOn, _TMR1RunOn
    MOVE?BB    _TMR1RunOn??HIGHBYTE, TMR1H
    MOVE?BB    _TMR1RunOn??LOWBYTE, TMR1L
    MOVE?CT    000h, _PIR1??0
    MOVE?CT    001h, _T1CON??0
So how much to add to timer1 reload to compensate I wonder?
Looking at the data sheet these instructions all seem to need 1 cycle each? So I make that 8 cycles how much is that in TMR1 ticks?