Eaton 1302s were the ticket for my '69 400 vert with A/C and all factory parts intact. "Stock" were 3" too high and drop springs put it on the rebound snubbers. 1302 are 1/2" above dead level right out of the box, should settle to level within 1K miles. That is with stock height rear springs, when choosing front springs you will need to take into account height at rear measurement point and match it. Tire, engine, and rear spring changes will change "stock" to modified.