Just checked my files on the 1988 350. The aluminum heads on the corvette version of the L98 TP1 350 get raised exhaust ports and revised valve head and seat angles for an increase in flow. They are identified by casting number 10088113. Camaro specific L98's are still equipped with iron heads. Both L98's get the LB9 Camaro (305 TPI with manual transmission) camshaft which increases intake and exhaust valve lift by 0.0011 inch and 0.015 inch respectively, and adds 4 degrees of exhaust valve opening duration. The changes boost Corvette horsepower to 245 and IROC-Z horsepower to 230. Self-aligning rocker arms are introduced on all Gen 1 engines. Throttle-body fuel injection is introduced for 350 trucks. This is the last year of any carbureted 350.