Well, I don't know if it has anything to do with the rearend(broken posi), but I'm getting a bad jerk until I reach 2000 rpm's then it stops and runs fine..I've been told this is from the flywheel(hot spots) but why does it do this in each gear..it does it in every single gear until it goes over 2000 rpm's then stops..can someone please tell me for sure what may be wrong..could it be something from the rearend or flywheel related..I have cartek in car with an aluminum flywheel...I appreciate any input

 

You may be experiencing an issue due to the flywheel weight. The engine is lugging/surging, probably because you are not creating as much inertia as with the steel flywheel, so the engine has to work harder to operate smoothly. I'm sure you noticed the engine revs up and down quicker, this is due to the lower inertia. If you have stock gears this will be amplified, and can also damage the clutch disc over time (break out the hub).

This is, assuming you do not have any tuning issues.

 

Ditto. Any reduction in rotational inertia will magnify a surging problem. You running a big cam? Split duration? Probably will need PCM tuning to increase timing advance at the lower load/rpm ranges.

 

The car has run perfect up until now..only mods I have are air lid, cutout, ftra..I haven't done anything to my car for a long time..the clutch grabbed real hard and never had this problem up until now..from 1st through all the gears below 2000 rpm's, it just jerks back and forth, I don't know if this is related to the broken posi or not but lots think it isn't and of course I'm clueless..car ran great for 2 years now everything is wrong