Swapping in a 95 TBI 454, adios 91 TBI 350

[Hopper]

Hello everyone,

New to site, new post, hoping for some help.

I been beating up the google search bar and kept liking what I have found on this site. You guys have lots of good info. I believe I have all aspects of my swap figured out other then the best route for my computer. I'm swapping out my worn and high mileage 91 TBI 350/4l80e for a 95 TBI 454/4l80e. The engine comes complete top to bottom minus the wiring harness and the computer due to the fact the truck had a cab fire and those items where trash. I hope to use my factory harness and....

Is my best option to have a chip made/burned and put it into my computer? (Is that a dumb question?) or should I look for a 454/4l80e factory computer and just run that as is? or get the right computer and still have a PROM burned? Is there a computer code I can use in reference when looking for the correct computer?

These might be very simple things that I can still search and find but I've been sifting through so much I need a break. I know some of you know this info like the back of you hand. Thanks for any help given.

[myburb]

My opinion would be to switch to computer that came with that setup. Would probably have been 7427 running $OE or $31. If you can't find a harness you could probably modify your original. I think on the net there is articles on repinning.

[dave w]

I like the option of re-pinning the 91 TBI computer connectors so you can use a 95 454 computer. Here is a link to how I did the conversion: http://www.gearhead-efi.com/Fuel-Inj...out-Directions!

Basically re-pinning allow you to use the 95 454 computer with the 91 harness. A few from the original 91 harness might need to be lengthen?

The 95 454 throttle body might need a 700R4 TV cable bracket modification?

dave w

[Neukam]

Repining to the later pcm is probably your best option using a 16197427 or 16196395. If you're going to use the transmission from the donor, you may have to change the connector for the transmission as well. I'm not an expert on the subject, but there were changes to the 4l80e over the years. The PCM doesn't need to be specific to a 454, but the memcal does. The memcal contains the code to run the engine and transmission as well as the knock filter circuitry and limp home mode circuitry. A new chip can be burned to replace the one on the memcal to change the calibration, but it must be a v8 memcal, and I'm not sure if the 454 used the same knock circuit, so it would be best to start with a memcal that matches your setup.

Info about transmission differences: https://youtu.be/Bjap2Th8tIE

Info on $0E: http://www.gearhead-efi.com/Fuel-Inj...Information-OE

[dave w]

I watched the transmission video posted above. Awesome information on the mechanical differences of the 4L80E.

I'm wondering what internal electrical / electronic differences there might from the early 4L80E 1991 - 92 vs. the 1993 - 95 ($OE & $31) electrical / electronics.

dave w

[Neukam]

A transmission guy would know better than me, but it is likely to be electrically the same internally. They probably had issues with the old style connectors leaking or breaking and redesigned it. Don't take my word for it, though. Do your own research. Maybe call Baumann Electronic Controls. They sell aftermarket transmission controllers for these transmissions and others. They would know if there's any differences in the electronics or control strategy.