Looking at buying a new Z71 probally tomorrow. Cant really get a clear answer on miliage differences between the 342 and the 410 gears. Tested the 342 gears this morning pulling the boat and it was less than stellar performance. OK but needs more grunt in the 20 mph to 50 mph range. Looking at the 5.3 HO motor.
Does anybody know the difference in gas miliage between the two?
Also does anyone got any info on the 5.3 vortec HO. It has about 310 HP. Has an aluminum block and aluminum heads. Any worrys about the aluminum heads doing all the pulling?