Predator tunes

[DolSVT00]

I know I can get a mail order tune But........
I plan on upgrading my upper and lower pullies and my T stat to a 160 ( I have them in my garage)and I dont want to pay twice for a tune.
my problem is I have the 90mm maf so I use the boxed diablosport tunes currnetly, well when I load the Factory HP tune for 90mm maf everything is good and the same goes for the 87 Octane tune for 90mm maf, but when I load the 91,93 Octane 90mm maf tunes I get a missfire at low steady rpm's under driving load. Anyone know how to remedy this?

Yes I have new plugs gaped at 0.32
Yes I have checked vaccuum lines
Yes I have a new fuel filter
Yes I have new 02 sensors(all 4)
Yes I run sunoco 93 snd lucas octane boost