Is 300 hp possible from a tbi

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df2x4

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and a wiring harness

http://www.nelsonperformance.com/?page_id=850

All I really find are wiring harness for a 1998 and newer 4l60e to 4l80e conversion (ebay has a bunch too), but not my 4l60 to a 4l80e.

do such harnesses exist?

Just to clarify, that harness would work for you if you had a 4L60E. 60Es and 80Es all use the same plug for the most part. I actually used that harness in my '97 60E to 80E swap, along with their pinned input speed sensor harness. But from what I'm gathering here you have a 700R4, which is basically the same transmission but I don't believe they have a wiring harness at all. (Hence the TB cable) I could be mistaken as I've never been up close and personal with one. (EDIT - Looks like they do have some, but it's very minimal and just controls lockup.) Pretty sure that's why L31Max said you'd have to add all the wiring for the transmission and a VSSB.
 

C2500

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What year is your truck if it's 88-92 you have a 700R4. And they can be built to take power. How 93-94 as far as I know are the same 95 is a stand alone year. 96-99 have the black box ecu and is completely different again.
My 88 C2500 came with a thm400.
 

westsoundred

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Just to clarify, that harness would work for you if you had a 4L60E. 60Es and 80Es all use the same plug for the most part. I actually used that harness in my '97 60E to 80E swap, along with their pinned input speed sensor harness. But from what I'm gathering here you have a 700R4, which is basically the same transmission but I don't believe they have a wiring harness at all. (Hence the TB cable) I could be mistaken as I've never been up close and personal with one. (EDIT - Looks like they do have some, but it's very minimal and just controls lockup.) Pretty sure that's why L31Max said you'd have to add all the wiring for the transmission and a VSSB.


yea, this is where I'm confused. Since I have the 700r, how do I get to teh 4l80e? Where does the VSSB go? what other edits need to be made (if any) to the wiring harness since I have the 700r?
 

884x4310ci

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Yeah heard bad things about monster transmission.
I always used B&M stuff. I looked at buying there crate trans. But found it cheaper to buy the kits and get my local trans guy to build it.
 

westsoundred

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df2x4

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yea, this is where I'm confused. Since I have the 700r, how do I get to teh 4l80e? Where does the VSSB go? what other edits need to be made (if any) to the wiring harness since I have the 700r?

VSSB - Not sure.

As far as the wiring for the harness though, I can give a little direction. Once again, download your factory service manual for the year of your truck from the thread I linked earlier. Find the pinouts for the PCM connectors, and the pinout for the 4L80E transmission wiring harness plug. Run all the wires for the pins in use at the transmission plug, and connect them to the appropriate pin at each plug.

Another thing to consider... This isn't the route I would go personally as I like having OD, but you could always swap in a TH400 and avoid all the electronics.
 
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