Holley Terminator EFI Install

[Ryan Hubbard]

I installed the Holley Terminator TBI EFI system in my 71 C20 pickup a couple weeks ago. I also have it controlling my 4L80E transmission. Here is the spec for my truck:

Engine
350 4 bolt main bored .030 over
Edelbrock Performer RPM Heads
8.5:1 CR
Manguson Eaton Rotor Supercharger (12 PSI Pulleys)

Transmission:
4L80E

Rear Axle:
Dana 60 with 3.55 gears and Detroit Locker

The install went pretty well, I had a TCI transmission controller installed in the truck so I just reused the hole in the fire wall for the Terminator wiring and mounted the computer on the glove box door. ( I have a billet aluminum glove box door) I also used the Holley Fuel pump kit with the filters, fuel line and fittings.

I also installed a small cap HEI electronic distributor so that the Terminator system could control the timing for the engine. I am still using my MSD 6AL ignition box too.

Since I am running a roots blower, I had to change out the MAP sensor to one that referenced the manifold vacuum/pressure after the blower. I just cut the plug of the wiring harness and connected a new plug and some longer wires and told the ecu that I had a 3 bar Map sensor.

Once I got the system installed, I followed the instructions and was able to set the initial timing and got the engine started and running. Once I got the engine running it took a little "tweeking" to get everything dialed in.

After the initial starts and tweeking, I started driving the truck and noticed a big improvement in drivability. I have now put over 1000 miles on the truck with this system on it and towed my other 71 K20 pickup over 600 miles and was able to get 9 mpg towing while still maintaining 75-80 mph on the interstate. (Before anyone says anything, my truck has 4 wheel disk brakes and trailer brakes and I was following the posted speed limits). I had done a lot of work on the carb for this truck and it was a well tuned carb but still not as nice as this system. I am driving another 700 miles tomorrow without the trailer or truck and I will see how that drive goes. But I was getting around 13.5 mpg with out the trailer. I am going to tweek the tune a little on the trip tomorrow and see if I can get a little better mpg. Not bad for a truck that has 550 Hp and over 500 LbFt of torque.