Re: Internal vs. External Coil in GM HEI
Unfortunately I have seen only 'installed' external-coil HEI and I dont recall the wiring layout.
The problem I'm having is that I was sure the external coil HEI's were used only in 75&76. I think you are fine to use what you have as long as it isnt computer-controlled and being a 1978 HEI I dont think you need to worry about that.
What type of vehicle was it?
For cleaning really dirty HEI's I use a wire brush and brake parts cleaner. You can dismantle these things almost entirely and do a thorough job if needed. Make sure to relube things when done.
85 CJ7, 350TBI ,T19 4spd
'00 TJ Sport