a lot of the gm truck came this way . roller block and flat.yes it a roller block i justed did one that came from gm with a flat hyd cam .this is now a roller engine yes the shorter push rod spider for the stock lifters and retaning plate for the roller cam if you go with the small bolt pattern on the top gear for the step nose cam i would use that type of cam and the stock gm roller lifters and the gm retaning plate for the cam and timing set and a set of custom push rod oh do not to forget to run the gm melonized gear for the steel core cam if you use a gm core gm