LM7 swap in 92 1500

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david lucka

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I have an LM7 engine and the engine in my 92 recently spun a bearing and i want to put in the LM7 engine into it. I want to run the original 700r4 transmission. What all would i need to do and change? I know wiring and stuff needs to be changes, but what would i need to do to the wiring and what would i need to do to mount it to the transmission. I know i need to move motor mounts.
 

RDF1

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The 700r4 has a TV cable? If so you will need to hook that up and have it adjusted correctly.
Trans bolts to the engine no problem.

You can get the engine mount adapters from summit racing for $40 I think?

I can't Rem if the torque converter bolts up to the 5.3 flexplate or if you have to enlarge one hole.

PCM needs tuned and the harness needs to be setup.

First swap can be a nightmare. Next one is a lot easier..

Sent from my SAMSUNG-SM-G870A using Tapatalk
 

david lucka

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The 700r4 has a TV cable? If so you will need to hook that up and have it adjusted correctly.
Trans bolts to the engine no problem.

You can get the engine mount adapters from summit racing for $40 I think?

I can't Rem if the torque converter bolts up to the 5.3 flexplate or if you have to enlarge one hole.

PCM needs tuned and the harness needs to be setup.

First swap can be a nightmare. Next one is a lot easier..

Sent from my SAMSUNG-SM-G870A using Tapatalk
Alright. What does the TV cable do? What do you recommend on tuning the PCM? And from my understanding i heard that you use the 5.3s harness and you have to change some pins and and it hooks right up? Or do i have to buy a special harness? Also would the flex plate from the 5.7 possibly work for the 5.3?
https://www.summitracing.com/parts/mor-62555/overview/
Are these the adapter plates?
 
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RDF1

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Think of it as a Throttle Valve for the transmission.
http://www.cpttransmission.com/tech_tvcable.htm

Black Bear Performance
Ive been dealing with Justin for 10+ years. He has been awesome on all the tunes ive gotten from him on all kinda different setups.
http://blackbearperformance.com/

These are mount adapters are $35
https://www.summitracing.com/parts/icb-551628/overview/make/chevrolet

Ive never tried to hook up the LS harness to the GMT400 Truck harness for gauges and such so im no help there. But someone makes a harness that plugs right into the engine/trans/PCM to the truck factory harness.
These folks i just found in a search, ive never used them tho.
http://www.currentperformance.com/shop/direct-fit-custom-wiring-harness/

http://www.azproperformance.com/88-98-GM-Truck-LS-Swap.html

http://www.gmt400.com/threads/gmt400-to-ls-harness-questions.32099/

What i did was just use a Andriod Tablet and a Bluetooth OBDII adapter. All the guages i need are on it.
Or if im tuning i just use the laptop for the information.

The 5.7 flexplate wont fit the 5.3 crank. But you should be able to use the 5.3 flexplate and bolt the trans up to it.
Id pull the converter and flexplate, Mate them outside the truck to make sure one of the bolt holes doesnt need opening up.
Just double check the distance from converter pads to flexplate.


If you want to do the engine wiring harness yourself. Orange wires get 12V+ all the time, Pink wires get 12v+ Ign Fused power, Black wires are ground.
 
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