Cylinder heads are generally not the best place for a high current ground. The only ground path to the block is through the head bolts, which almost always are a good connection, but not always. If the head doesn't have a good low resistance path through bolts (intake is even worse for a ground) current can flow through the valve train, and that isn't ever going to be good.
Most high current grounds are to the block or to a component that if (in some rare case) develops a high resistance any arcing or electrolysis will be harmless to bearings or critical surfaces. The bellhousing would be an excellent choice, and the timing chain cover nearly as good.
Best places to worse places in order for high current grounds:
Bell housing and engine block
Timing chain cover
Heads
Intake
The computer ground is near the computer, and most critical ground leads float back to that point. The LAST thing you want is the engine grounding back through the computer so your choice of multiple grounds is a good idea. You don't want the block floating up from starter current.
There are a few safety issues created when locating a battery in the trunk, one is the chance of fire if the positive lead to the solenoid (or starter relay) gets pinched to ground. I always relocate my starter solenoid to the trunk so the big heavy cable is only active during cranking, and it can go straight to the starter terminal to save lead length and keep the voltage up. I run a lighter number 4 wire up to a terminal where the old starter relay or solenoid was located, and I fuse that wire with a fuse link because it is always hot. But that's just me. I like full voltage when the engine is hot and not having to worry about a cable getting pinched and starting a melt down.
Tom
Most high current grounds are to the block or to a component that if (in some rare case) develops a high resistance any arcing or electrolysis will be harmless to bearings or critical surfaces. The bellhousing would be an excellent choice, and the timing chain cover nearly as good.
Best places to worse places in order for high current grounds:
Bell housing and engine block
Timing chain cover
Heads
Intake
The computer ground is near the computer, and most critical ground leads float back to that point. The LAST thing you want is the engine grounding back through the computer so your choice of multiple grounds is a good idea. You don't want the block floating up from starter current.
There are a few safety issues created when locating a battery in the trunk, one is the chance of fire if the positive lead to the solenoid (or starter relay) gets pinched to ground. I always relocate my starter solenoid to the trunk so the big heavy cable is only active during cranking, and it can go straight to the starter terminal to save lead length and keep the voltage up. I run a lighter number 4 wire up to a terminal where the old starter relay or solenoid was located, and I fuse that wire with a fuse link because it is always hot. But that's just me. I like full voltage when the engine is hot and not having to worry about a cable getting pinched and starting a melt down.
Tom
