Converting 4L60-E to Turbo 350 with NP241C

[HotRodPC]

Someone called me and left a detailed message. I don't know when it was, I had 37 messages to listen to. Whoever you were, didn't leave me a phone # and the part of their forum ID was bleeped out with bad reception and I didn't catch it all. Seemed like DBD something and I have no clue who that would be. Hit me up here or call me back. Not sure how anyone got my phone #, only a few have it. But anyway, get back with me.

 

[Vbb199]

Someone called me and left a detailed message. I don't know when it was, I had 37 messages to listen to. Whoever you were, didn't leave me a phone # and the part of their forum ID was bleeped out with bad reception and I didn't catch it all. Seemed like DBD something and I have no clue who that would be. Hit me up here or call me back. Not sure how anyone got my phone #, only a few have it. But anyway, get back with me.

That was me

 

[HotRodPC]

Aha, yep, now that I see your name. Makes sense. That first part of your message was garbled and I couldn't make it out. Now I forget what I was going to suggest you do. Getting old sucks. So does staying so busy. I don't listen to Vmail very often so it's usually better to hit me up in text if I don't answer. And I don't generally answer unknown #'s cuz I don't care to buy an extended warranty for my vehicle.

 

[Ken B]

the older i get the less I answer the phone....

 

[HotRodPC]

I got your text tonight, I was on a tow run to Tulsa on the turnpike so I didn't respond. Practice what I preach you know.

So all the Th350's are 27 spline output shaft. So if you want to replace you 4L60-E with a Turbo 350, with it being a 4x4 you'd have to do some mods to a passenger car Th350 with the 6in output shaft. As in cut off the output shaft. You'll also have to get a bracket for the detent cable to your throttle linkage and add a vacuum line to you intake manifold for the vacuum modulator. Otherwise should be able to get it to bolt right in, same driveshafts and all with the adapter spacer. I have a thread, converting from 700r4 to Th350. That will give you some help on what you're going to do.


https://www.gmsquarebody.com/threads/adapt-4x4-th350-in-place-of-700r4.1181/

 

[HotRodPC]

What year truck are you working on anyway? What engine? How hard you plan on wheeling it? You can do some mods to the 4L60-E also to make it a bit more tolerable. It'll still not be as durable as the Th350 but it'll tolerate some abuse.

 

[cstew47]

Maybe I missed it, but, why change a 4L60 for a TH350? That sounds like a downgrade. I have put 700r4's/4L60's in all my vehicles. It lets me run a lower gear ratio and still have streetability with the overdrive.

 

[Raider L]

@cstew47.

Yeah I was thinking the same thing, why make that change? Unless you are going to do some heavy towing or you plan on racing but even then a dang 200R4 can be beefed up for racing. I don't know that much about hopping up 4L60's I'm sure it's done. Did you put a old school big block in your truck and it doesn't have all the computer plug-in's to run the trans would be about one of some reasons to change the trans.?

 

[RecklessWOT]

@cstew47.

Yeah I was thinking the same thing, why make that change? Did you put a big block in your truck would be about one of only reasons to change the trans.?

AFAIK that's exactly what happened. If this is the truck I think it is some hillbilly engineer mad scientist ************ type put a 502 in a '79 C10...

A PO might have decided to try to make it more modern with some garbage new electronic transmission and he wants to go back.

Unless he decided to put it in one of the burbs, that would explain the newer transmission... and make the truck even ******* cooler... Please tell me you put the 502 in your Burb Vince...

 

[Vbb199]

AFAIK that's exactly what happened. If this is the truck I think it is some hillbilly engineer mad scientist ************ type put a 502 in a '79 C10...

A PO might have decided to try to make it more modern with some garbage new electronic transmission and he wants to go back.

Unless he decided to put it in one of the burbs, that would explain the newer transmission... and make the truck even ******* cooler... Please tell me you put the 502 in your Burb Vince...

My 79 is the carrier of the big block, and its not running a wimpy 4l60/350, its got a th400 i built myself rated for 800hp

@cstew47.

Yeah I was thinking the same thing, why make that change? Unless you are going to do some heavy towing or you plan on racing but even then a dang 200R4 can be beefed up for racing. I don't know that much about hopping up 4L60's I'm sure it's done. Did you put a old school big block in your truck and it doesn't have all the computer plug-in's to run the trans would be about one of some reasons to change the trans.?

Offroad machine, big tires, 1 tons
4l60e is completely trashed internally on the 1-2
(only.speeds i run)

Maybe I missed it, but, why change a 4L60 for a TH350? That sounds like a downgrade. I have put 700r4's/4L60's in all my vehicles. It lets me run a lower gear ratio and still have streetability with the overdrive.

Th350 has bigger clutch surface than a 4L60e, but this isnt a street machine, its a s10 blazer on 1 tons and 39.5 boggers that chews up and spits out ****** 4L60e's (5x now)

 

[RecklessWOT]

My 79 is the carrier of the big block, and its not running a wimpy 4l60/350, its got a th400 i built myself rated for 800hp



Offroad machine, big tires, 1 tons
4l60e is completely trashed internally on the 1-2
(only.speeds i run)


Th350 has bigger clutch surface than a 4L60e, but this isnt a street machine, its a s10 blazer on 1 tons and 39.5 boggers that chews up and spits out ****** 4L60e's (5x now)

Not quite exactly what I thought, but completely what I expect

 

[Vbb199]

Not quite exactly what I thought, but completely what I expect

https://www.gmsquarebody.com/threads/vinces-79-c10-shortbox.32993/page-7#post-682911

 

[RecklessWOT]

https://www.gmsquarebody.com/threads/vinces-79-c10-shortbox.32993/page-7#post-682911

how the hell did I not know that thread existed???

Awesome, looks like she's coming along great