Description
Perfect replacement for a mild to moderate 403 rebuild restoration. Great driveability. Works well with the factory rocker arms. Factory compression ratios of 7.8 to 8.2. Enhanced ignition suggested but not a must. Works well with 3.23 gear ratio and works even better with 3.42. Works fine with factory exhaust manifolds. Headers will give improved torque output and increased HP. For automatic and manual transmission. RPM range 1800-5000. Tip: Due remember that these Trans Ams are not light, and happen to be under powered when comparing weight and factory HP. Increasing numerical gear ratios to a 3.42 or even a 3.73 really help out.
@.050 221 int.
@.050 226 exh.
Lobe separation 108
Int. Lift .484
Exh. Lift .480
suggested lifters https://oldsperformanceproducts.com/product/lifters-hydraulic/
