12SEC SS

iTrader: (5)

Ok, I got a 6.0L LQ6 out of a 2003 Silverado SS, with a magnacharger supercharger on top of it, as well as truck wiring and truck computer. This is all going into a '94 Caprice, which now has an LT1. I am planning on bolting up my LT1 4L6E and I ordered the adapter. I also ordered Cartec mounts, and watching for a 98-02 pan on ebay to send to Street & Performance so that I dont have to cut up my crossmember. Street & Performance also makes headers that fit, I will most likely order those as well... I have some questions that I cant find answers to.

1. The truck had a drive by wire throttle body. What do I need to do to swap to the cable driven throttle body, besides the obvious throttle body? can i still use the same truck computer? how is the wiring harness effected?

2. The truck came with a 4L80E I assume, is the transmission plug the same as the 4L60E, and will the truck computer be fine with running a 4L60E tranny, or do I have to get like an F-body computer?

3. If I swap to an f-body computer, is the truck wiring still going to work, or are computer plugs or wiring different?

FirstGen

iTrader: (10)

Try Speartech one of our sponsors. They will be able to answer your questions...

kirtondog23

I am not positive on this but I think the plug might be the same between the two trannies but the wiring is a bit different so you might need to get a wire added to your harness and move a few of the wires around. . Might want one if the sponsors to just rework your harness so you dont have to think about it.

99 BUCKET

my pops has that same truck, it does not have a 4l80. have fun man, we have his set up with a maggie too!

ryanvv355

iTrader: (17)

The LQ9 should have came with a 4L65E. LQ4's got the 80E in 3/4 tons. To eliminate ETC, I dont know about a LQ9/60E combo, on a LQ4 you have your ECM reflashed as a 2003 Express van 2500 and run wires for the TPS and IAC. You might look into a 2003 express 1500 5.3 program and have it tuned for the LQ9..just a thought.

'JustDreamin'

1.) It might be easier and cheaper to just install the DBW throttle pedal in the car than the wiring harness changes, tuning, and throttle body required to go to cable. Just a thought.

2.) SS's came with 4L65E's, which are slightly (just slightly) upgraded 4L60E's. They should plug in the same way. The range selector switch (black box on the side where the shift lever is on the side of the trans) may be different (not sure) but you should be able to swap to a late model one and have it be plug and play. I would be concerned about the 4L60E surviving, but that's a completely different issue....

3.) If you do the above things, you don't need any real changes (maybe delete the rear O2's) so there's no real reason to swap to an f-body computer.

Just my thoughts, though....

'JustDreamin'

tooblue

I did a very similar swap on a 95 Caprice LQ4/4l65. The LT1 Trans will not work with out some work. Will not directly bolt up=properly also the wiring is different. You may find if you do use adapters to get the Lt1 tranny to bolt up the convertor will never lock-up properly.

I converted my install to a manual throttle body and also swapped to the ls6 manifold. I would just use the Truck PCM and have the person who does the programing take care of "VATS, rear 02s and manual throttle body (if thats your choice) I used a guy named Bryan Herter. On the truck harness, if you plan to use the existing harness that came with the Lq9, you will find that you will need to eliminate quite a few wires/pins. Depending on where you plan to but the PCM you will need to change the lengths of most of the wires to fit spot selected. I had about 100 hours in my harness but wanted it to fit in a specific place and also wanted use the existing Relays and fuses in the Caprice. I used the pin outs from the LQ4 and Pinouts from the Caprice to get everything figured out. FUN Conversion !!! Roger