66mustang. why is my car dieing. on 1990 Ford Mustang GT

66 mustang 302. car is dieing with no warning after idling for 2 minutes or 10 minutes. sometimes longer and sometimes not so long. it does the same thing when driving it. my temp guage pegs out hot when i turn the ignition to the on position. replaced the temp sending unit. still doing the same thing.

not sure what to try next. any suggestions will be greatly appreciated.

1 answer
The problem described sounds like the chassis is trying to ground though the temperature gauge. I would make sure there is a good ground strap between the engine block and the firewall since the battery is only grounded to the engine block. There needs to be a heavy ground strap between the block and chassis, otherwise the chassis can ground though the transmission and differential arcing gears and bearings.