Lt1 into 79 impala

Hey guys I was doing some research on swapping an lt1 into my 79 Impala. I have some questions about the wiring involved in the swap.
1) If I would want to keep my th350 trans, would the stock wiring harness still work?
2) Could I keep my stock gauge cluster even though I will have an lt1 motor, harness, and ECU?
3) What for wiring would be involved in the swap? I was thinking of the Painless Performance harness but it says its for the 4l60e tranny. Could I still get the wiring harness and use my th350 trans?

Thanks for the help.

Thats gonna be a badass ride. I've got a 4 door pillar-less 66 Impala with a 327 and a glide, Still unsure of what I want to do to it, either a stock resto, a patina'd body with a badass motor, or dropping it on a lt1 b-body frame. Good luck on your project man.

Thanks man, the main reason that I want to do the swap is to put a modern motor in it. You just don't see many older cars with newer engines!

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Originally Posted by impala101

Thanks man, the main reason that I want to do the swap is to put a modern motor in it. You just don't see many older cars with newer engines!

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I know man that will be a badass car

Thanks. That's what I'm hoping for!

Attachment 4317There she is.:drool:

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Originally Posted by impala101

Hey guys I was doing some research on swapping an lt1 into my 79 Impala. I have some questions about the wiring involved in the swap.
1) If I would want to keep my th350 trans, would the stock wiring harness still work?
2) Could I keep my stock gauge cluster even though I will have an lt1 motor, harness, and ECU?
3) What for wiring would be involved in the swap? I was thinking of the Painless Performance harness but it says its for the 4l60e tranny. Could I still get the wiring harness and use my th350 trans?

Thanks for the help.

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It would be a pretty easy swap no matter the trans you use. If it were mine I would run the 4l60e because of the overdrive and ability to tune shift points through the PCM. If you were to use the TH350 the stock LT1 wiring harness would work fine. You just wouldn't hook up the 4l60e connectors and get the PCM tuned so it doesn't get upset that the correct trans isn't there. You could keep all the stock gauges by using all the correct 79 Impala sending units. If you are using the TH350 your factory speedo will be fine, but with the 4l60e you will probably need to add a small box that takes the vehicle speed sensor signal to spin a motor that turns your speedo cable. Wiring is not bad if you get a complete harness with underhood fuse box. The swap is pretty easy and it has all been done before. Research goes a long way and keeps the surprises to a minimum.

Alright thanks that helps me more! I think I will put the 4l60e trans in. I was thinking and I'm just going to get new gauges. What would be needed for the speedo gauge to work? Like with the 4l60e trans since its an electric gauge (so I think) An with an electric gauge? I'm going to look on google for a diagram if I can find one. Thanks again guys for the help.

I'm still confused about the wiring though. Like if I would get a universial harness from jegs how would the stock accessiaries (turn signals, head lights, ect), connect to the stock lt1/4l60e wiring harness? I just don't understand how it would all be wired up to work?

The vehicle wiring harness and the engine wiring harness are two separate wiring harnesses. The only place where the may come together would be the fuse box. The headlights, turnsignals, ect aren't really related to the engine management portion of the car. Do you already have the LT1 engine and transmission? If not I would seriously look into buying a complete donor car. If you were to find a wrecked LT1 Caprice, Impala, Roadmaster, or Fleetwood you would have almost everything you would need to get the swap done. Depending on how hard you look you may be able to find a donor car for the price of that Painless harness. The factory engine harness on any of these cars is pretty simple if you look at a wiring diagram and it comes with an under hood fuse box so it is basically a stand alone deal.