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Just so were clear...I haven't done a swap like this before, so bare with me.....
what i have is a 1974 3/4ton truck with a 383/th350/205, what i have to put into it is a 2008 LC9 Aluminum block 5.3 and a 2009 6L80E. which i plan on putting a turbo on top of
I recently got the motor and trans, Advanced Adapters makes an adapter for the 205 transfer case right up to the back of the 6L80, no big there.
the issue I'm having out of the gate, is wiring. I have the harness(minus the pedal) from the 2008 truck the engine came out of, BUT it is for a 5.3/4l60 combo, the 6L80 is different that the TCM is inside the trans. so i either need to find a way to remove the 4l60 and add the 6l80 wiring and connector.
Id like to do it, ill say low cost, as i know its not cheap, but you can end up with a custom harness for into the 1000$ range
I am still searching the site for wiring info. if anyone has done this swap or has some wiring diagrams, any help is appreciated.
well i got lucky today, found a wiring harness on ebay from an 09 silverado in very good shape, had vin and rpo list, matched my engine but with a six speed, so ill use that one to strip down to what i need
Pictures ended up being bigger than intended....After only 3 years I managed to get some pics posted, and get a custom wiring harness...not a whole lot of free time these days but I have been chipping away at it. Motor and trans are in, and set, had some exhaust pieces bent up locally to make the hot cross over. Ended up with a LJMS stage 2 4.8/5.3 turbo cam and all matching pieces, Had a couple pistons that were a bit burnt on top, had some pitting, got a set of ebay pistons that lowered it from the 9.9:1 CR to a 9.6:1 CR from earlier LC9's. Timing cover with dual an fittings for oil drains, the transmission is a stock 6L80E and will be mated to a NP205 transfer case. Had a custom hose made for the power steering, truck needed a steering box for the last 15 years finally got one, a Redhead so the steering is checked off. Need to order injectors, mount the transfer case and put in the front driveline so I can finish fabricating the hot crossover pipe. Also bought a turbo manifold and an On3 78mm turbo from a guy on the internet, this will get replaced later with a quality turbo, but this is my first LS turbo anything so wanted to go budget on certain parts in case it grenades on take off
04-17-2018, 05:15 PM
Gen IV 5.3/6L80E into a 1974 gm truck 
