67 twin turbo dart

Thats not good enough. All grounds go to battery. Block heads intake ecu chassis all go to battery. It may not be your problem but i chased an electrical gremlin for a year and it was a bad ground. Its so common for folks to think a ground to the chassis is good enough that there are hundreds of videos on youtube addressing that very problem. Once my grounds were improved so many things i didn’t even know were a problem were fixed.

Good to know, will figure out a way to tie it into the car to connect to the fuse block that goes to the battery ground directly. I'll get the firewall gromnet to connect the heads and intake to the fuse block ground