The intake is not the ideal location, you want it bolted to the block itself. While the intake is metal there are a couple of points of connection with gaskets between them that make it just not the best spot. I recommend using one of the bolts that holds the starter on myself. It goes straight to the block and the starter draws more current than anything else in the motor so having it go straight to the chassis(assuming your chassis is properly grounded to the battery) is the best way.