[Tom Wells]

Tee,

Nothing obvious.

Here's my question: is the all-in weight of the rear really 1050 pounds?

Most lightweight (i.e. thin fiberglass, small block etc) Cobra kits come in around 2250-2500 pounds and usually have a rearward weight bias of 52-55%

Also recall your calculation needs to include you, a mostly full tank of gas, all fluids etc.

Springs for race-oriented cars are usually a bit stiffer than for a mostly street cruiser.

Tom