I would run 14* timing as cold as it is.
Maybe 16*
The h-pipe won't make much difference at all.
5 hp=about .05 ET
You should go mid to hi 14's
Don't bother w/ a dyno right now, Use your best time slips and go to stangnet or mustangweekly and plug those numbers into the calculators for estimated hp. You will need an accurate weight of your car, not a guess.
A lot of truck stops charge around $5 to weigh-in
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4.10's,long tubes & 75 shot...Goes 12.50's
Check it out at
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