Lift bar support

Putting lift bar on my modified and was wondering which is the better option
for supporting it side to side...support on frame rail or support from rear end

frame support is best, keeps it all in line and doesnt move around like the rear end mount. Just make sure the lift bar has heims on the rearend end.

Rear support won't bind up, some late model chassis that used frame supports are going to the rear tie instead due to the increased amount of movement. If your tie bar is not long enough then it can stop upward movement which can cause the rear to shear the contact patch of the tire and you will loose traction. I have seen several chassis encounter this problem. You also have to be very careful of the angle of any mount and location as it can cause other problems like hitting the driveshaft.
The rear tie seems most consistent of the two as the angle of movement is consistent and added traction or bumps will not change it as much as the chassis tie. Either mount is going to allow the lift shock/spring to change angle, it just depends how they are setup as to how much.