The L-82 Corvette and Z28 Camaro In 73/74 had a 350 4 bolt main block with forged flat top 2 valve relief pistons, high lift 450/460 hyd. cam, 2.02/160 valves and screw in studs and guide plates. A Z28 had only two rear axle ratios available 3.42 or 3.73 with Posi- Track standard. My first one was a TH400 and they were equipped with a high stall convertor 2400 rpm. Both of my Current Z28s were born with Borg Warner Super T-10s. All Z28s of that era had Corvette style alum valve covers and dual snorkel air breathers.