If you have a '73 - '76 V8 K-member then use it. One difference of note would be the type of engine brackets as this later model went to the 'fail-safe' style (round insulators) which would require the corresponding brackets off '73 or newer A or B-body car. I would also measure your torsion bar diameter as the stock 6 cyl. bar may be only 0.83" so you should therefore find a pair of 0.87 inchers.