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I am Canadian!
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Well, I finished swapping a Carb 350 into my truck, i am using the stock TBI PCM to control the 4L60E. and here is how!

DO NOT ATTEMPT THIS IF YOU HAVE EMISSIONS!

Transmission Control Via TBI PCM:

First off, Here is what the PCM needs to operate the 4L60E

-VSS
-CTS
-TPS
-A RPM Signal

Now i did the exact same thing 04SilveradoMykk did in his thread with his Vortec PCM, But my truck was stuck in limp home mode.

Mykk's Thread-> http://www.gmfullsize.com/forum/showthread.php?t=145089

I am running a Stock GM HEI distributor, and it is what i would recommend for a similar swap, I WOULD NOT keep the TBI Distributor, you have no clue as to what the PCM is gonna do without seeing fuel.

Now with a TBI engine, there is no crank sensor telling the PCM if its running.

It took me about a week to figure out what to do, but when i did its easy as 123.

1.Find the plug that used to plug into the Distributor and lead to the PCM.

2.Find the Purple/White wire

3. Take Wire and run it into the TACH position on your HEI Distributor.

4. Done!

Picture of wire with a quick disconnect.
P6150339.jpg


Here is a Picture of my TPS on my Speed Demon 650CFM
P6150338.jpg


Picture of whole setup
P5240152.jpg


Here is a Video of me leaving my driveway, as you can see my tranny is functioning proper (I still manual shift it) if the purple/white wire wasn't hooked up, i wouldn't get 1st or OD.

th_MOV01285.jpg


as you can see in the video, my Speedo, Coolant temp and all other gauges work like factory (My Oil PSI gauge isn't working cause my Oil Sender is gone, Replaced with an Autometer unit)

So now that your 4L60E is working, lets carry onto Fuel.

Fuel:

I sent up my fuel system a little different then Mykk, Here is what i used.

-Stock TBI In-tank Pump
-Holley 12-803BP ByPass Regulator (http://www.summitracing.com/parts/HLY-12-803BP/)
-Marshall 0-15PSI Gauge, (Not shown)

It is VERY Important that if you are keeping the stock pump, you HAVE to have a return, i dont care what anyone else says, just capping off the return is gonna kill the pump, THE RETURN IS THERE TO COOL THE PUMP!.

Picture of my setup.

P5080144.jpg


Those are the stock TBI Fuel Lines, i just bent them a bit and cut off the fittings and installed some new ones.

I then ran a hose barb out the left side to the carb, shown here.
P5240152.jpg


at first it ran great, but i still wanted to check my PSI, so i added a gauge. using some fittings we had laying around, i dont have any pictures of it, sorry.

I found that my demon likes 6.5-7PSI. and the Holley Regulator is factory set at 5PSI.

After this, the engine ran very well, i would recommend this swap to anyone wanting a bit more out of their engine.

-Josh
 

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hi guys new here very gratefull for this info but i have a few hopefully simple questions but with a twist (the twist comes later)

let me get this straight. So i have a regular oldschool 350 carb motor i want to swap in where my tbi motor was. my truck has a 4l60e so all i need to make everything work properly as factory is attach the old tps to my new carb and attach the purple/white wire to a regular hei dizzy

is that it? will all my old temp oil wires etc just fit an old regular 350 etc?
 

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Built, not bought.
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hi guys new here very gratefull for this info but i have a few hopefully simple questions but with a twist (the twist comes later)

let me get this straight. So i have a regular oldschool 350 carb motor i want to swap in where my tbi motor was. my truck has a 4l60e so all i need to make everything work properly as factory is attach the old tps to my new carb and attach the purple/white wire to a regular hei dizzy

is that it? will all my old temp oil wires etc just fit an old regular 350 etc?
Pretty much, you'll need a fuel pressure regulator also with a return line, either a Holley 12-803BP or Mallory 4309.
Also a Carbed intake for your motor, and that's it.

Unless your lucky like me and have a 700R4, then you don't need a TPS just a bracket and your rollin.

And all my guages work like factory.
 

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thanks BB!

so what are these below and how do they get to work with a old carbed 350 and 4l60e?

(truck is tbi 350 with 4l60e the motors coming out and i have a regular old 350 to go back in)


First off, Here is what the PCM needs to operate the 4L60E

-VSS ???
-CTS ??? crank trigger sensor?

-TPS fit the old tpi unit to carb right?
-A RPM Signal. attach purple/white wires to dizzy right??

once im clear on this il move onto the twist/s i mentioned
 

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Built, not bought.
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I know very little about the 4L60E, but from what I've read the only difference between 94Shortie and 04SivaradoMykks swap and mine is the TPS sensor.

In short you'll cut the purple / white wires that power your coil and attach them to the HEI distributor ( purple = power / white = Tach)

Run your fuel lines from the bypass fuel pressure regulator to the carb.

Hook up your engine vitals like, temp sensor, oil pressure, ALT wires, and A/C wiring if you have it and ditch all unused wiring like EGR, 02 Sensors and such.

The serpentine belt system from your TBI motor will bolt right up to the other motor.
That's it really, well you'll need the TPS for your carb also.

This is my carb swapped motor out of an 85 Monte Carlo SS. Before I removed, shrink taped the unused wiring.


012-1.jpg


Good luck.
 

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really gratefull for the help/advice there b/b ive a couple more questions admin please fell free to move this if it needs a new thread.

il be running lpg (propane) so the fuel reg etc shouldnt matter and it will most likley be an impco 425 propane carb

the question is could i use say a ,,mega jolt,, eddis mapable ignition instead of the dizzy and if so where would the 2 ,,new,, hei dizzy wires connect? this way i can cheaply/easily get the best out of the timing etc for lpg OR i could simply fit apropriate lpg advance springs?? to the hei dizzy?

anybody know? i think i read somwhere about a guy with lpg fleet of c1500s?
need a build recipie for max mileage/torque lpg motor but maybe thats for a new thread
 

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What about the MAP sensor? The PCM will need to know if the engine is under a load. The shift points are gonna be different for a truck under 3/4 throttle with a 2,000 pound load than a truck under 3/4 throttle with no load.
 

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Ok i have a question. Let me explane.
I put a older 350(rebuilt long block) into a 97 silverado(blownup engine and no money so working with what i got) 4X4 with a 4l60e.Everything else is stock including the ECM and wireing

I have mounted a TPS to the carb , Map, front crank sensor, knock sensor, Both water temp sensors. Can not use cam position sensor or the 97 dist.

The original dist(97 has 3 wires) so from reading this all i really have left to do is hook up the 1 wire shown above to the old HEI dist tack output and my 4l60e should work and shift like intended?

I have not finished the swap yet and have not even started it. Would be great if i started it and the trans worked as intended.
I realize this is a little different then the one shown above but really all the stuff the trans needs will be hooked up IF there is a tach wire for the dist.
Thanks for the help guys:worship:
 

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I gotta ask why on earth would you revert to 100 year old technology. Carbs have been deprecated for 30+ years, that's longer than I've been alive.

TBI is very friendly and easy to tune with the right computer. Www.dynamicefi.com check out the ebl_flash board. MPFI is more involved to install and tune, though more efficient.
 

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I Did this setup in my 96 chevy 1500 but i can't seem to get the fuel pump to stay running. It turns on when u turn they key but doesn't stay on after you start it. I didn't hook up the purple/ white wire to the tach pos. Could this be why its not staying on?
 

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I have a 1996 Chevy Tahoe would like to transplant pre 1972 350 into. What all will I have to do to make tranmission work , etc.. Nice truck motor out.
 

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Different cross member, kick down cable, drive shaft and possibly fly wheel. I cannot remember if the spacing is different off hand.

But either way that question has nothing to do with this thread
 

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Well, I finished swapping a Carb 350 into my truck, i am using the stock TBI PCM to control the 4L60E. and here is how!

DO NOT ATTEMPT THIS IF YOU HAVE EMISSIONS!

Transmission Control Via TBI PCM:

First off, Here is what the PCM needs to operate the 4L60E

-VSS
-CTS
-TPS
-A RPM Signal

Now i did the exact same thing 04SilveradoMykk did in his thread with his Vortec PCM, But my truck was stuck in limp home mode.

Mykk's Thread-> http://www.gmfullsize.com/forum/showthread.php?t=145089

I am running a Stock GM HEI distributor, and it is what i would recommend for a similar swap, I WOULD NOT keep the TBI Distributor, you have no clue as to what the PCM is gonna do without seeing fuel.

Now with a TBI engine, there is no crank sensor telling the PCM if its running.

It took me about a week to figure out what to do, but when i did its easy as 123.

1.Find the plug that used to plug into the Distributor and lead to the PCM.

2.Find the Purple/White wire

3. Take Wire and run it into the TACH position on your HEI Distributor.

4. Done!

Picture of wire with a quick disconnect.
P6150339.jpg


Here is a Picture of my TPS on my Speed Demon 650CFM
P6150338.jpg


Picture of whole setup
P5240152.jpg


Here is a Video of me leaving my driveway, as you can see my tranny is functioning proper (I still manual shift it) if the purple/white wire wasn't hooked up, i wouldn't get 1st or OD.

th_MOV01285.jpg


as you can see in the video, my Speedo, Coolant temp and all other gauges work like factory (My Oil PSI gauge isn't working cause my Oil Sender is gone, Replaced with an Autometer unit)

So now that your 4L60E is working, lets carry onto Fuel.

Fuel:

I sent up my fuel system a little different then Mykk, Here is what i used.

-Stock TBI In-tank Pump
-Holley 12-803BP ByPass Regulator (http://www.summitracing.com/parts/HLY-12-803BP/)
-Marshall 0-15PSI Gauge, (Not shown)

It is VERY Important that if you are keeping the stock pump, you HAVE to have a return, i dont care what anyone else says, just capping off the return is gonna kill the pump, THE RETURN IS THERE TO COOL THE PUMP!.

Picture of my setup.

P5080144.jpg


Those are the stock TBI Fuel Lines, i just bent them a bit and cut off the fittings and installed some new ones.

I then ran a hose barb out the left side to the carb, shown here.
P5240152.jpg


at first it ran great, but i still wanted to check my PSI, so i added a gauge. using some fittings we had laying around, i dont have any pictures of it, sorry.

I found that my demon likes 6.5-7PSI. and the Holley Regulator is factory set at 5PSI.

After this, the engine ran very well, i would recommend this swap to anyone wanting a bit more out of their engine.

-Josh
I have a set of vortec heads, performer rpm intake, headers and an hei distributor I plan on putting on my Tbi 95 k 1500 with the 4l60e, I'm wanting to go carb to open up my choice of cams plus I don't drive it in the winter much. My question is with all the factory sensors hooked up and the purple and white wire hooked up to the hei dis will the tranny shift normally or do you have to manual shift it ? Sorry to fire up such an old thread but any help would be appreciated.
 

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I am Canadian!
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Discussion Starter #16
I have a set of vortec heads, performer rpm intake, headers and an hei distributor I plan on putting on my Tbi 95 k 1500 with the 4l60e, I'm wanting to go carb to open up my choice of cams plus I don't drive it in the winter much. My question is with all the factory sensors hooked up and the purple and white wire hooked up to the hei dis will the tranny shift normally or do you have to manual shift it ? Sorry to fire up such an old thread but any help would be appreciated.
It should technically. But I never got mine working 100% and just went to a th350.

I would stay tbi if u can
 

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94shortie
I have followed your instructions on this conversion. My 95 tahoe is still stuck in limp mode. I am ahaving issues with the wiring. From what i have gathered the white wire goes to the tack and the purple goes to the batt side correct? The white wire, is that the one that is in that 4 plug on the dizz?or is it from the other plug? The only sensor you hooked up was the tps sensor correct? Would a bad wheel speed sensor cause it to stay in limp mode?
 

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94Shortie was last seen:

Aug 19, 2017


Good luck getting a response from him :roflmao:
 

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94shortie
I have followed your instructions on this conversion. My 95 tahoe is still stuck in limp mode. I am ahaving issues with the wiring. From what i have gathered the white wire goes to the tack and the purple goes to the batt side correct? The white wire, is that the one that is in that 4 plug on the dizz?or is it from the other plug? The only sensor you hooked up was the tps sensor correct? Would a bad wheel speed sensor cause it to stay in limp mode?
The wire to hook to the HEI Distributor is purple with a white stripe. Hook that wire to the tach spot on your distributor and you’re good .
 
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