COMP Cams Camshaft C43 266H-R12For '87 '94 GM 4. 3L 262 cid 90. V6 Non Balance shaft Engines with Hyd. Roller Cam. Works with Throttle Body and Sequential Port Injection with Aftermarket Chip. Good Low End and Mid Range. Adjustable Valve Train Required. Balance shaft equipped 4. 3L engines were introduced in '92 but GM continued to produce the previous version until '94. Non Balance shaft 4. 3L's ('85 '94) shared their timing cover with the small block Chevy V8 engine. The. Balance