what can i expect

ik this is a ltx forum but im thinking bout going to ls1 and im wondering what times i could expect out of this car

2002 firebird formula
170000 miles
m6
long tubes
slp loudmouth
some suspenion upgrades
slp lid
msd ignition coil packs and all

i wouldnt brag on myself but im a pretty good driver with a manual just wantin to know what i could expect or if i should judt keep my low mileage lt and mod it.

either car will be my dd so i was just thinking i could add 4.10s to that m6 and run good times and still get good mpgs just wondering guys

thanks for your time

id stick w/the low mileage car. mine has 182k and everytime i take it out im always nervous about what is goin 2 break next.