I was cruising at around 45mph so I punched it but it just doesn't really take off like a jet could it be my stock gears or my stock underdrive pulley??

 

1: From 45mph I noticed the same, I don't think it is going to take off "like a jet" from that speed.

2: Could be your gears, 2.73???

3: Underdrive pulley has nothing to do with take off/launches. It has to do with reducing rotating mass so the engine can rev easier.

 

Anyone else know what could it be?

 

Was the car faster at one time? Or are you just trying to make it faster and want us to tell you what to change. What gears do you have? If you do have 2.73, I would find a new use for them as a door stop.

If I bust 2nd at 45mph my LT1 will go sideways.

 

i dont know for sure with an ls1 but with my lt1 (automatic) it kinda had a 'dead' spot between 35 and 50. anything after 30 and it wouldnt downshift into 1st and under 50 it wasnt really into the powerband yet. if you want to get rid of the dead spot, or move it, gears are a good way. i mean, the dead spot is still faster than alot of cars on the street, but it just isnt pulling as hard as it is when it is in the prime powerband.

 

Yeah, ~45 mph is kind of a crappy spot ..... with 2.73's, it's just out of reach of a 1st gear drop, and with lower ratios, I don't know if the tranny would be grabbing a good gear or not for that speed?? Even with 4.10's, I don't think ~45 mph is a particularily good "sweet spot".