Trans options for 78 Cheyenne

JSJJ388

JSJJ388

GREEN GREMLIN
Joined
Aug 31, 2016
Location
HAMPTONVILLE, NORTH CAROLINA
So, my brother has ended up with our old farm truck after some horse trading. He just bought himself an 7.3 Ford truck and doesnt need the chevy, so hes wanting to sell it. Ive been looking for a full size truck because occasionally my dakota just aint big enough.

Truck run down:

Mildly built 350 (mild cam, head work, and long tube headers)
Minimal rust
Rattlecan paint job in matte black
electric/hydraulic steel flat/dump bed with wood side rails
Not much works as far as the interior goes. Temp and voltage are the only working gauges if memory serves
Trans is toast


Which brings me to my point, what are my options on a trans? It has a 350 now, but it doesnt have overdrive AFAIK. If I get it, itll see some highway use, so overdrive would be good.

Anyone wanna guess what hell ask for it? He hasnt given me a price, but Im certain his starting number will be ungodly high.
 
Picture of said truck, doing exactly what I plan to do with it.

20170702_174139.jpg
 
Automatic I'd go 4l80e with a stand alone controller. I'd spend the extra money for that over a 700r4. I've had my fill of 700r4s not holding up over the years.

If you want manual I'd go nv4500.
 
Half ton 2wd, no trans, Id say $1000 tops. If he has seen the current market for those trucks, he will want alot more than that for it.

As for trans, if you are wanting to stay cheap, an OD trans might be a challenge. I agree with Tim, that a 4l80 or nv4500 is a good option. In order to get a 700r to hold up, you will need to put way too much $$ in it.

you might can find a nv3500/ax15 for a decent price, but it isnt a very HD trans.

you might consider having the th350 rebuilt, but put a lower 1st gear and upgraded parts in it, with a trans cooler. Balance that with the rear end ratio/tire size and you could still be decent on the highway.
 
Thanks for the quick replies. Doesnt have to fly down the road, just needs to hold 65ish with a solid load. Truck has hauled a lot of cattle and hay, but its always just been 2 lane back roads at 45 MPH.

Im good with a manual, but its auto stock. Would that be difficult to swap over?

Realistically, itll drag my waggy around or any other junk I decide to bring home.
 
700r4 will bolt up and will survive just fine provided you know what a TV cable is and how to adjust it.

No one wants to hear that, but its true.
Same gear packs, same clutches/frctions as a TH350.
Seriously buy a rebuilt kit for each and dump them out side by side and get to granular part numbers.

The difference is in the TV setup vs the vacuum modulator. An improperly adjusted TV cable will starve your clutch packs and burn them up. Not maybe. Not it will shorten the life but its hard to say how much. It will slap burn the trans up. Lots of folks just "wing it" with a TV cable "close enough" and then demonize the 700.

Now I am NOT suggesting a 700 is as strong as a th400 or 4l80. It isnt.
But that 4l80 conversion would cost you more than Id be willing to pay for that entire truck. A bone yard 70 could be picked up and rebuilt for $6-700.

But to be fair, to @shawn and @UTfball68 favorite argument that truck isnt built to run 65 mph pulling another vehicle down the road. That truck was built when the nationwide speed limit was 55mph. Regardless of RPM, your brakes, suspension and really entire truck isnt adequate for 65mph towing of much.
 
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what rear end ratio is in it now?
Quick and easy bet for me would be a TH400 off the marketplace and swap in a rear axle with more highway friendly gears.

SM465 in 2wd are also dirt cheap, you could toss a 3.08 rear under it and be pretty highway friendly, the creeper will get the load going, the 1-2 shift will bring the suck.
 
shelby27604 said:
what rear end ratio is in it now?
Quick and easy bet for me would be a TH400 off the marketplace and swap in a rear axle with more highway friendly gears.

SM465 in 2wd are also dirt cheap, you could toss a 3.08 rear under it and be pretty highway friendly, the creeper will get the load going, the 1-2 shift will bring the suck.
Click to expand...

I think 3.55, but Im honestly not certain.
 
guessing that is ~30" tire. With no overdrive.
3.55 @ 65mph
2nd gear 4,000rpm
3rd gear 2,700rp.

3.07 @65mph
2nd gear 3,500rpm
3rd gear 2,400rpm

I would go 3.08 and be slow when taking off from a start, gives you a comfortable kick down rpm on the highway.
 
Ron said:
700r4 will bolt up and will survive just fine provided you know what a TV cable is and how to adjust it.

No one wants to hear that, but its true.
Same gear packs, same clutches/frctions as a TH350.
Seriously buy a rebuilt kit for each and dump them out side by side and get to granular part numbers.

The difference is in the TV setup vs the vacuum modulator. An improperly adjusted TV cable will starve your clutch packs and burn them up. Not maybe. Not it will shorten the life but its hard to say how much. It will slap burn the trans up. Lots of folks just "wing it" with a TV cable "close enough" and then demonize the 700.

Now I am NOT suggesting a 700 is as strong as a th400 or 4l80. It isnt.
But that 4l80 conversion would cost you more than Id be willing to pay for that entire truck. A bone yard 70 could be picked up and rebuilt for $6-700.

But to be fair, to @shawn and @UTfball68 favorite argument that truck isnt built to run 65 mph pulling another vehicle down the road. That truck was built when the nationwide speed limit was 55mph. Regardless of RPM, your brakes, suspension and really entire truck isnt adequate for 65mph towing of much.
Click to expand...
I don't disagree, but the th350 didn't survive either... and for some the TV cable is next to impossible to get adjusted exactly right.

Any od tabs will require a new shifter, i believe. It was a factory option in this trucks, so maybe it's just the indicator.

Sent from my SM-G970U using Tapatalk
 
A 3.08 rear gear with a SM465 and 31 ish tires is about a perfect setup for a square body without overdrive. It’s similar to having deeper gears with a overdrive trans because of the low first gear. The wide gear splits will probably take some getting used to. That’s how mine is setup just a 4wd, and it will pull a trailer with a Jeep going 75 easy. I just stay in the right lane on the really big hills and down shift to third when it’s down to about 55 and it will pull that all the way to the top. It takes longer to get anywhere towing compared to a new truck but that’s part of it.
 
tknopp said:
Doesn't TCI sell a kit so you can delete the TV cable but still have the correct pressures?
Click to expand...
AFAIK only if you are willing to go full MVB...but I haven’t worried with a 700 in 10 years
 
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