LS swap for my 75

[Zoomad75]

Getting close on my 5.3 swap. DrityLarry's done most of the heavy lifting for me, but I did all the research on the swap since neither of us had done the LS stuff before. He's done 8.1's but the GEN III stuff is a bit different due to the change in engine mounts but as far as the EFI and electronics go it was the same as his 8.1 swaps.

Here's a little sample where we are at on mine.



Carb isn't the way to go with a LS engine. Yes you'll get it running, but the advantage to this swap is the EFI. I kid you not this thing starts like any modern fuel injected truck. Twist the key and go. My 75 with it's 350 and quadrajet never started like that. I had the q-jet dialed in well too. Summertime it was fine, but once it got cold it sucked and would take 20 minutes to warm up. Driveability is better, fuel economy is better and it's not as overwhelming as one might think.

As far as mating a LS engine to a 700r4 it's not a big deal either. I used a Bowtie overdrives TV made EZ kit. They make a kit specific to the Vortec truck intake or the Vette intake. Instructions are clear and the cable/bracketry takes the guesswork out of the cable geometry.

Big tip. Save yourself a headache and get a custom harness rather than reworking a factory harness.

A simple option is running a system that uses an MEFI4 controller. It is a simplified setup and the same controller used on the Ramjet crate engines. Painless sells a harness and MEFI4 kit as well as a couple of others. It's not as complex in the wiring and it doesn't require efilive to tune.

This is my first one and I'm sold. If another 5.3 or 6.0 falls in my lap it might end up in my Nova.