what transmission is best for me

[canadianboy]

Hey guys,
I recently bought a 78 GMC K25. it has a blown th350 tranny (5 sided pan?) because someone put mismatched gears into the axles. my question is what trannys should i look at for a replacement? the truck has the skinny brake from a manual and the hole for a floor shifter. i have a sm465 from my current dd that i could swap in as i prefer a manual but my gf wont drive a stick... also i am moving to the city in the near future and would rather not burn out a clutch in traffic. what are my options for both auto and manual trans? what transmissions have od?

i plan to take out the 3" bl and leave the 6" sl and run 35s (for now)

also how hard is it to change and set up gears in a d44?

 

[Driver4r]

Hey guys,
I recently bought a 78 GMC K25. it has a blown th350 tranny (5 sided pan?) because someone put mismatched gears into the axles. my question is what trannys should i look at for a replacement? the truck has the skinny brake from a manual and the hole for a floor shifter. i have a sm465 from my current dd that i could swap in as i prefer a manual but my gf wont drive a stick... also i am moving to the city in the near future and would rather not burn out a clutch in traffic. what are my options for both auto and manual trans? what transmissions have od?

i plan to take out the 3" bl and leave the 6" sl and run 35s (for now)

also how hard is it to change and set up gears in a d44?

Its one of the easiest things ive honestly learned to do.

As far as tranny's, I would recamend a 4l60/4l80. 4l60's are alot more plentifull, and if you treat it right, it will last.

I have a question tho, Why did it mess up your trans?? When i had 4.11's in the front and 3.08's in the back, i was affraid of blowing apart the 203. Why did your trans let loose befor the tcase? I would think that it would *** up the 205 befor the trans.

 

[canadianboy]

The 205 stood up to the difference, but the transmission was always under load. It was like it was always hauling a heavy load. That and the 37s didn't help. Back axle is 3.73 and front is 4.09.

What would I need if I were to attempt to swap gears? I have a set of ford axles available in 4.10 ratio but I don't think the rear gears will fit my 14bff. They are also 3/4 ton axles. So I am thinking if swapping the damaged 4.09s out if the d44 for a set of 3.73.
This is also a consideration for a transmission. I am planning to run 3.73 gears an don't want to overwork the trans.


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[canadianboy]

would a 4l60/80 bolt to my existing 205 and allow me to reuse my driveshafts? thats why i am considering another th350. what would be my best manual option?

 

[HotRodPC]

Skip the 4L60-80-e transmissions. Unless you have a ton of cash for a controller, and willing to give up the strength of a Th350 which is stronger than a 700r4/4L60-E and you won't have the expensive adapter for the NP205 either. Your cheap way out of this mess and if you don't want to set up gears in the Dana 44, is to find you a very common 3/4 ton Full Floater or Semi Floater 4.10 ratio rear axle to match that Dana 44 ratio, rebuild your current Th350 since they are so cheap to rebuild, or have rebuilt and rock and roll it. 4.10's are OK without OD if you're running 35 or 37 inch tires and driving 65-70 mph on the highway. You can convert that to kilometers yourself since your from Canada and familiar with that.

So IMO, that's the cheap way out. Swap the rear axle, and rebuild your current Th350 and go with it. The Th350 will work fine if it's not dragging or fighting the gears and binding.

 

[canadianboy]

Skip the 4L60-80-e transmissions. Unless you have a ton of cash for a controller, and willing to give up the strength of a Th350 which is stronger than a 700r4/4L60-E and you won't have the expensive adapter for the NP205 either. Your cheap way out of this mess and if you don't want to set up gears in the Dana 44, is to find you a very common 3/4 ton Full Floater or Semi Floater 4.10 ratio rear axle to match that Dana 44 ratio, rebuild your current Th350 since they are so cheap to rebuild, or have rebuilt and rock and roll it. 4.10's are OK without OD if you're running 35 or 37 inch tires and driving 65-70 mph on the highway. You can convert that to kilometers yourself since your from Canada and familiar with that.

So IMO, that's the cheap way out. Swap the rear axle, and rebuild your current Th350 and go with it. The Th350 will work fine if it's not dragging or fighting the gears and binding.

the gears are chipped in the front axle or i would go with 4.10 rear. i can post a pic in the am and see what you guys think of the gears and if they're worth running. could i take the d44 out of my half ton and run it with 8 bolt hubs? or maybe the carrier/gears?

so th350 is stronger than 700r4/4l60? with 4.10 ratio and 35s i'm looking at 2300 rpm at 100kph (about 60-65mph). my current 77 with the 465 and i think 3.73s roars pretty good on 33s at 65mph in high gear. how difficult is it to rebuild a th350? what if any special tools are needed? what would the final cost be? is a shift kit worth the trouble/cost? also is there a manual tranny that would be a straight forward swap reusing my tcase and dshafts?

 

[HotRodPC]

OK, makes sense. If the D44 needs gears anyway, yeah that direction on that issue.

Yes, the Th350 is stronger and will tolerate more abuse than a 700r4/4L60-e. Only Automatic option stronger is a Th400. I wouldn't even start to guess the cost of a rebuild in Canada. I'd call around. There are a few special tools needed to build it, but they can also be improvised. Check the Auto Trans section. I have a few build threads on Th350. Look it over and see if it's something you think you can handle. If you have the right SM465 and adapter, along with clutch pedals and all, SM465 isn't a bad option either.

 

[canadianboy]

Ok thanks. I have a 465 with fresh clutch in my 77 that is being replaced by this 78 once it's ready. I could rob everything off of it for the swap if I go that route. I'll have a look at rebuilds on here to help decide as well.


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[bucket]

The th350/205 is a good setup, probably be easiest just to have that rebuilt and run it. Then you don't have to take apart your useable truck.

 

[farmerchris]

expensive option,but would let you use the hole in the floor and still give the manual shifter feel. http://lokar.com/product-pgs/shifters/shifter-product-pgs/floormount-shifter.html

 

[HotRodPC]

The th350/205 is a good setup, probably be easiest just to have that rebuilt and run it. Then you don't have to take apart your useable truck.

That's my suggestion too...

and regear the front axle to correct those chipped teeth and it will last just fine.

Certainly the cheaper way out all the way around.

 

[GreaseDog]

Put another Th350 in it, and put 4.10s in both axles. Should be about perfect with 35s.

 

[v2500burb]

What are your thoughts on me swapping a built 700r4 in my burb
It has a th400 now
A buddy of mine... His dad had been building transmissions for 30yrs and can build me one for what I could sell my th400 for
Any changes I would have to make to my drive line??


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[bucket]

What are your thoughts on me swapping a built 700r4 in my burb
It has a th400 now
A buddy of mine... His dad had been building transmissions for 30yrs and can build me one for what I could sell my th400 for
Any changes I would have to make to my drive line??


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I'll soon be taking out my built 700R4 and swapping in a th400...

You will need to swap in a 27 spline t-case input, or just the entire t-case (241). From my measurements, the drivelines are the same length.

 

[canadianboy]

expensive option,but would let you use the hole in the floor and still give the manual shifter feel. http://lokar.com/product-pgs/shifters/shifter-product-pgs/floormount-shifter.html

I think i would end up trying to shift and try to jam the trans into park on the hwy with that thing...

i like the thought of being able to reuse everything. (dshafts, tcase etc) so i will probably stick with a th350. is installing and properly setting a new gear set something i should attempt? any special tools i would need? and while i'm doing this, any inexpensive lsd units for a d44 front axle? ive never even had rear posi till the g80 in my current truck but my dad is still surprised i even try to go where i do. may as well make this thing a go-anywhere-mobile.