JimmyRich
Member
Hello from Texas! My question is What all specifically does it take and estimated cost of going with 4 spd auto trans upgrade in my 66 Sport Fury with 383 -727 now. Thank you
Trans upgrade
- Thread starter JimmyRich
- Start date
Just Carbs
Well-Known Member
I suggest you consider a 440 first.
If you don't have a 3.55 axle ratio or 3.73, can't use OD except over 60mph or so. Resultant OD ratio would be 2.49 or 2.61, approx.
Might need some tunnel hump dents to clear the transmission. OD can be toggle-switched, I believe, whereas the lock-up converter is governed by spring/hydraulic pressure?
Doing the late model ZF TF would require an expensive adapter bellhousing and electronic controls adapted to the engine and car.
Remember, too, that a higher-revving engine can be more fuel efficient (with the right combination) than a lugging engine with lower intake manifold vacuum.
In the several fuel economy tips books Chrysler put out in the later 1970s, they quoted a 1% fuel economy increase with every 3% change to a higher (lower number) gear ratio. In reality, NO way to justify the trans swap on fuel savings alone. IF that's what you are after.
Most 3.23 geared C-bodies run about 25mph/1000rpm where those with 2.76 usually run about 28mph/1000rpms, typically (considering the tire sizes they came with, back then).
Just some thoughts and observaitons,
CBODY67
Might need some tunnel hump dents to clear the transmission. OD can be toggle-switched, I believe, whereas the lock-up converter is governed by spring/hydraulic pressure?
Doing the late model ZF TF would require an expensive adapter bellhousing and electronic controls adapted to the engine and car.
Remember, too, that a higher-revving engine can be more fuel efficient (with the right combination) than a lugging engine with lower intake manifold vacuum.
In the several fuel economy tips books Chrysler put out in the later 1970s, they quoted a 1% fuel economy increase with every 3% change to a higher (lower number) gear ratio. In reality, NO way to justify the trans swap on fuel savings alone. IF that's what you are after.
Most 3.23 geared C-bodies run about 25mph/1000rpm where those with 2.76 usually run about 28mph/1000rpms, typically (considering the tire sizes they came with, back then).
Just some thoughts and observaitons,
CBODY67
LocuMob
Fluid Technician with a hat
You could add a Gear Vendors overdrive unit, $3,195 and some transmission work and a shortened driveshaft, or get a 4 speed trans with whatever associated parts, some tunnel modification and you'd possibly be in the ballpark in terms of money spent.
Anthony 71 Paisley
Member
I did a 46rh in my 71. Cost wasn't terrible of you ask me. The hardest part for mine was retaining the factory column shifter. There's no provision on the ultrabell for factory linkage .
If you have to send everything out obviously Cost would be much more. Also if you have to have the trans built. It gets expensive quick.
Ultrabell housing 450$(ish)
Tunnel mods 0$
Shorten driveshaft 200$ (ish)
Fab x member maybe 100$ in steel and parts /a few hours of fab/welding
Shifter linkage 100$ ( ish )
Cost of trans ( I found mine for 500$)
Figure out a way to control OD/LU 100$ (ish)
Running 4:11 gears cruising at 70 and being able to hear yourself is worth the time /work and headache IMO.
If you have to send everything out obviously Cost would be much more. Also if you have to have the trans built. It gets expensive quick.
Ultrabell housing 450$(ish)
Tunnel mods 0$
Shorten driveshaft 200$ (ish)
Fab x member maybe 100$ in steel and parts /a few hours of fab/welding
Shifter linkage 100$ ( ish )
Cost of trans ( I found mine for 500$)
Figure out a way to control OD/LU 100$ (ish)
Running 4:11 gears cruising at 70 and being able to hear yourself is worth the time /work and headache IMO.
1970FuryConv
Old Man with a Hat
Do you have a link to the Ultrabell housing?
Anthony 71 Paisley
Member
Prices went up.
Also , 10 or 10.5" convertor is largest that'll fit. So have to figure that in too. But no matter what you have to get convertor.
.
Also trans cooler lines are larger on 46rh. I went with A/N & an external cooler. Someone could use adapters to save a little
JW Performance 92457: Ultra-Bell Bellhousing Big Block Chrysler to TF-727 - JEGS
Also , 10 or 10.5" convertor is largest that'll fit. So have to figure that in too. But no matter what you have to get convertor.
.
Also trans cooler lines are larger on 46rh. I went with A/N & an external cooler. Someone could use adapters to save a little
JW Performance 92457: Ultra-Bell Bellhousing Big Block Chrysler to TF-727 - JEGS
73Coupe
Senior Member
Dang, $700 for that chunk of cast aluminum.
Ultra-bell J.W. Performance Transmissions 92457 J.W. Performance Ultra-Bell Bellhousings | Summit Racing
Transmission 518RH
Transmission 518RH
1970FuryConv
Old Man with a Hat
What years of 727 transmission does this fit?
Or is it mislabeled and really it only fits later transmission models?
Example
We're not bolting it onto my 1971 727
Fits all 727 or 518 transmissions. IT IS NOT JUST A BOLT ON! If you look at the casting line on the 727 in the photograph ( above the 433 - 8) you can see the general area where the housing must be cut to allow the Ultra-Bell to mate to the case it then can be bolted on using the front pump bolts. Check out FABO/FBBO websites there are some pictorials over there IIRC.
1970FuryConv
Old Man with a Hat
Thanks. I guess I'd need to buy longer grade 8 front pump bolts.
My front pump bolts are 5/16 thread. Any ideas on what stress this set up can take before the bolts break?
70bigblockdodge
Old Man with a Hat
I have not done a automatic. I have put a 4 spd manual overdrive 833 trans in 2 different cars. They are both are nice cruisers. My Charger has a mild 440, 3.23 gears and gets a easy 15+ mpg on the highway at 70+ mph and you can hear yourself think. The other car is a '69 Coronet/Super Bee with a 509 cam in it and flow master mufflers, also has 3.23 gears. It needs a bit more tweaking for fuel mileage. It's a pretty loud car in general, but it rolls effortlessly at 80+ mph at ~2700 rpm and you can have a conversation, although the wind noise through the windows is quite loud.
I did 1900+ miles in a week on power tour last June most of which would have been over 3000 rpm with a 1:1 trans, that just gets old after the first 8 hour day.
So do you need overdrive? No, but it sure is nicer than not having it.
If you have done road trips in modern cars with overdrive and then try to do a 6-700 mile day in you old car with anything lower than a 2.94 rear gear your going to hate it.
I did 1900+ miles in a week on power tour last June most of which would have been over 3000 rpm with a 1:1 trans, that just gets old after the first 8 hour day.
So do you need overdrive? No, but it sure is nicer than not having it.
If you have done road trips in modern cars with overdrive and then try to do a 6-700 mile day in you old car with anything lower than a 2.94 rear gear your going to hate it.
BTW there has been some discussion regarding the loss of mounting location for factory shifters, both column and floor. DO NOT throw away the bell you cut off, the factory mounting can be tig welded to the ultra-bell to facilitate factory mounting position. It is helpful to take photos and measurements before you cut. These can then be used to correctly position the proper mounting points.
It's for 518's primarily but I guess it could be used for a small block 727 to BB 727 but why? Internals are pretty much the same and could be swapped if you goal is to use a known good transmission, there were 10's of thousand 727's in the BB bolt pattern made and finding a case is easy. Other than the cable shifted version all 727 are primarily the same unless you consider deeper drums to house more clutches. However today there are some thinner clutches and steels that allow for more clutches in a drum. Yes there are a few outliers but they are not the norm.
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1970FuryConv
Old Man with a Hat
JEGS ad says 727, not 518. JW Performance 92457: Ultra-Bell Bellhousing Big Block Chrysler to TF-727 - JEGS
I was trying to learn. I asked the question because I did not know about cutting off bell housings. I thought 727 might have had a bolt on bell housing at some point.
70bigblockdodge
Old Man with a Hat
There was some adapters out there in the world for putting a 904 behind a big block smaller internals to be quicker at drag strip. Would do the same thing as 518 behind big block. I think most of them have gone away, seemingly replaced by ultra bell.
73Coupe
Senior Member
I can easily picture some jamoke taking a sawzall (with demo blade) to a 727 and massively flucking it up....
Just Carbs
Well-Known Member
I resemble that!
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