*Note: 50-State Legal. This camshaft has been granted a California Air Resources Board (CARB) exemption (an 'EO' number), or is a direct or consolidated replacement part. It is 50-state legal, per the manufacturer's application guide.

**Note: Beginning in 1987, most of the V-6 and V-8 engines were equipped with hydraulic roller camshafts. There are differences in the block to accommodate a cam retention thrust plate and the anti-rotation mechanism for the lifters. These blocks are identifiable by bolt holes for a cam retention plate under the upper timing sprocket, as well as bosses and tapped holes in the lifter valley for lifter retention hardware. The camshafts on these engines have a step nose and smaller bolt circle on the front of the cam. An earlier model camshaft may be used in these blocks by using the appropriate timing chain set and adding a thrust button when using a roller cam.
1988-99 Chevrolet 305 and 350 V-8 engines (and some 1987 350 V-8 engines) use a different configuration camshaft core than the 1955-87 engines and cannot be interchanged.

BUILDS MID AND UPPER RPM PERFORMANCE IN 1987 TPI ENGINES WITH 5-SPEED TRANS. AND ALL REAR GEAR RATIOS. ALSO FITS 1988-89 305 ENGINES W/5-SPEED AND 2.73 OR 3.27 GEAR RATIOS FOR MID-RANGE PERFORMANCE ADJUSTABLE FUEL PRESSURE REGULATOR RECOMMENDED FOR MAXIMUM PERFORMANCE. (50 STATE LEGAL FOR LISTED APPLICATIONS, C.A.R.B. E.O. D-225-22)