Fitech ultimate tpi question

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Jan 22, 2026 | 09:16 PM

madmaximus

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Joined: Feb 2009

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Fitech ultimate tpi question

Just received the fitech ultimate tpi today and not sure where to mount the ecm. I have an 89 formula 350. Does anyone know if the fitech harness is long enough to run the same way as the factory harness?

Jan 26, 2026 | 05:00 PM

maroe624

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Joined: Sep 2014

Posts: 749

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From: Los Angeles

Car: 92 Z28 Clone

Engine: Vortec 350

Transmission: T-56

Axle/Gears: 3.23 Torsen

Re: Fitech ultimate tpi question

Not long enough. Need to get creative

Mar 24, 2026 | 01:56 PM

SteveC68

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Joined: Dec 2010

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Car: 1989 IROC

Engine: 5.7L

Transmission: Auto

Re: Fitech ultimate tpi question

Watch this guys videos. He ends up mounting it inside, but I think he had to drill a hole in the firewall to get it there.

Mar 27, 2026 | 09:57 AM

dabomb6608

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From: Marion, IL

Car: 86 Trans Am/85 K5 Jimmy

Engine: 406 FIRST/350 TPI

Transmission: TKO 600/700R4

Axle/Gears: 9Bolt/10Bolt front & back

Re: Fitech ultimate tpi question

Quote:

Originally Posted by SteveC68

Watch this guys videos. He ends up mounting it inside, but I think he had to drill a hole in the firewall to get it there.

https://www.youtube.com/watch?v=oYvWYnDPvg0

Likely had to drill somewhere on firewall near the HVAC box. The factory used a decent amount of extra wire running up and over the underhood HVAC and then down the fender and into the passenger side kick panel.