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I wanna do the reverse swap, auto for 833, is it THIS easy?
https://slantsix.org/forum/viewtopic.php?t=22090		 Page 1 of 1
Author:  rock [ Sat Mar 03, 2007 11:13 am ]
Post subject:  I wanna do the reverse swap, auto for 833, is it THIS easy?
Hi folks,

I just can't stand it not having a project going. So I am thinking to take out my newly installed 833OD and its hydro clutch and put in a 904 to see how it runs. This is a daily driver truck, not a racer, though it is well built with new engine, 4bbl, 244 cam, big valves, and on and on.

A forum member turned me on to a late 1966 904 with a stock torque convertor. I have read the FSM for putting in a 727 cause I don't have a 904 book and it seems the process would be about the same. My vehicle is a '64 d100 and I had to fabricate a cross member for the 4 speed tailhousing, a carb linkage and most everything for the clutch, so no big deal if I have to make stuff for the 904.

BUT, is it really as easy as as it reads: pull out the 833, clutch and all, ease the torque convertor onto the tranny, bolt on the flex plate, and slide the tranny and torque convertor in the crank and bolt up to bell? (The crank has a roller bearing I put in for the 833 input shaft)

If so, this might be a piece of cake...seems like only a few hours work..except:

(1) What number teeth or part number speedo gear do I need for a 3.91 rear end with 28 inch tires?

(2) My racing friends told me to get another torque convertor, because they say that with my 244 cam and a 750 rpm idle, the engine will try to stall when I mash the gas. I have the threads in this forum and I STILL don't know the difference between stall and non stall in terms of what they do..

(3) I want to go back with a floor shifter, so is one about as good as another, looking in the Summit and Jegs catalogs...is $99 bucks about as good as $200, assuming I don't need a ratchet and reverse lockout?

(4) I reckon I will fabricate kickdown linkage and use as part of it a super six rod I have...other than getting the linkages to move the lever as needed, is there any tricks to this? For instance, BPE (Boucillon Performance Engineering has a cute looking kit for the 4bbl, but it looks simple to me to make one.

Thanks
rock
'64d100
Author:  Jeffc [ Sat Mar 03, 2007 1:04 pm ]
Post subject: 
Do you still got the bell crossmember? or has it been removed?
If it has not been removed you will have pan clearance problems
with the auto trans (clearance is close enough that pan will bang
the crossmember).
All the trucks 68 back to the 50s use the bell mounted crossmember
on manule trans.
For the 727 applications this cross was cut out on the factory floor
leaving about 6" of stub each side. The stub needs to be there
since the rear spring mount for the front is part of it.
Now the 904 is a little smaller, but not much, so you may run into
the same issues.

Remember, truck gross empty is around 3800+lbs full size in the early 60s,
lots of weight for a car 904...... my later 66 comes in at 4300.....
my 68 short at around 3700....

Oh, what year engine in the truck, post 67 904 or before 67....

Converter stall is the speed at which the converter moves fluid.
Low stall converters (stock) will have a stock stall speed of around
1200(+/-)rpm after which there will be not be stalling action.
Stall= engine speed vs trans imput shaft speed; higher engine
speed is allowed without slipping clutches inside the trans
because the conveter is doing the slipping instead of clutchs and bands.

A high stall converter will have a higher rpm rate, say 2100rpm or more,
thus letting the engine rev higher without trashing the trans clutchs.
This can be a real advantage at the 1/8 or 1/4 mile track
or with engines that will not run under 1000rpm because of camming.
At the track you pull up to the line, keep the engine at around 1200+rpm
with the brake on, making better HP and tork, light turns green off you go.
Doing that with a low stall converter very many times the trans will
not take it and go boom, because the clutchs will be forced to slip
to make up the differace and cooking the clutchs and bands.
Down side to high stall is they make a LOT of heat (biggest enemy of
a auto trans next to slipping clutchs and bands and plugged fliters) so big trans coolers
are a must; also, because of stalling, fuel use is much higher, not
all engine power is passed to the trans a low speeds.

Kind of in a nut shell, there it is....
Author:  rock [ Sun Mar 04, 2007 8:42 am ]
Post subject:  Many Thanks, Jeffc, really good summary for me, and ...
Many Thanks, Jeffc,

Really good summary for me. Maybe I might not be so hot to do the swap! I had an A745 3 speed before swapping in a 833OD. My truck came with the so called "universal" big cast iron bell, casting 22357414-2. That bell was for a low mount starter and has the 45 degree perches inward to enter of tranny to hold the hips of the bell....like a poly 318 bell. I had to cut out part of the "hip" rest to make room for the slave pull cylinder I put on driver side, and had to cut a minor notch in the center span (about 3/4 inch deep) so the very rear of the 833 case didn't tap on big bounces.

While the frame is a 64 Utiline, the engine is a 72 block and crank, just rebuilt. I am not sure you are referring to the kind of cross member I have. Reason is that my front leaf springs are not attached to any part of the cross member. They came attached to the frame.. if you visualize a frame like a 2 inch by 6 inch piece of lumber turned on its side so the wide dimension goes upward, my spring attachments are on the 2 inch side of the frame The crossmember also is riveted to the same narrow dimension but is under the spring bracket, having one flat strip riveted on top of the other to the frame. In other words the entire cross member could be cut out flush with the frame, not leaving any of the 6 inches you refer to, and no matter as to spring attachment. I reckon this is like so many things we get into...just try and see if the tranny will slide up?

Thanks again for the clarity of stall and non stall, and the caution of the 3800 lb. concern. That weight is why I didn't do the T5 yet, even though having the bell and adapter. I am looking for a truck T5 because it is short enough to have the shifter in front of a bench seat..

Cheers!
rock
'64d100
Author:  Jeffc [ Sun Mar 04, 2007 9:23 am ]
Post subject: 
May seem like the spring perch is "just rivited" to the frame, but
the crossmember is part of that, as it is rivited to the same area.
The crossmember helps give support to the perch by boxing the
frame in that area.
If your were to look a the 69 and later trucks, that did not use
the bell crossmember, that area is boxed in to support the spring perch.
However, you are correct that the old crossmember could be
cut back farther, just not all the way out. On the other
side the photos below show how they did it at the "factory"
on the auto trucks. How you do it up to you if you choose
to do the swap.....

The trans crossmember you are using is common to the 69 and later
trucks.
So should work just fine with the 904 application, since it
was also used with the 727 and manule trans.

Yes, that old bell was used for all the small blocks, slants as well
as the old flat head six, and has bolt patterns for all 3.

Not the best photo, lost the orig photo somewere, but
http://imageevent.com/jeffc/techstuff/t ... 4&x=0&p=24
http://imageevent.com/jeffc/techstuff/t ... =1&z=2&l=0
http://imageevent.com/jeffc/techstuff/t ... =4&s=0&z=2
Author:  rock [ Tue Mar 06, 2007 2:07 pm ]
Post subject:  Many thanks, what a dissertation and what great data!
Jeff,

Well, thanks hardly covers it! Man what a great data collection! You sure did the hobby a service in compiling it. On one hand though, it seems you clearly say the crossmember I have will "work, yet in the thread seem also to say clearly it won't work unless cut. SO, will it work uncut, or is the suggestion to make the assembly you show in the pictures and weld it to crossmember stubs?

Thanks
rock
'64d100
Author:  Jeffc [ Tue Mar 06, 2007 7:56 pm ]
Post subject: 
:D LOL, should have been a little clearer, the crossmember
that you are (should be) using for the rear mounted manule trans
should work just fine with the 904...... guess I could have
called it a trans mount or hanger.
The stock truck hanger
for the 727 was a bolt in, almost as strong as that rivited in
bell crossmember for the manule bell.
After 68 all these truck and truck into the 70s used
the rear mounted trans hanger (manule and auto).

Crossmember for the manule bell that is in your truck is not
compatable with anything other than the manule bell.....

Those (not so fancy, cut, bent and welded angle iron) factory "spanners" that attach to the
stubs are just bolted to the stubs, bolt holes should be in
the crossmember if you want to look for them, 2 each side,
4 per stub, 8 holes total for both sides together (2 spaners,
one each side of the stubs)....

I kind of dought that the spanners are even really needed
since trucks after 68 did not use a crossmember there
and there were really no frame changes after mid 65
other than that crossmember under the manule bell
and boxing the frame for spring perches.
But that's the way the factory did it.
Just wanted you to be aware.

Most of the time the factory cut could be called pretty crude,
ether just torched out or sawed out. Frist time I saw that,
on a auto truck, I though someone did it in their "back yard".
Next time I have one my auto trucks pulled apart, or part one
out that I picked up, I will shoot new photos......stuck with
what I got till them....

I will be starting a section for the Scamp soon showing the
4 speed swap as I do it......and we are getting ready to our spring
Sweptline bar-B-Q here at the end of this month so new photos
of that soon after.

That 62 listed below has been in the family since 68, cut my teeth
on it when I was a mear kid...... frist car was a 68 Ply Suburban wagon
just out of HS in 75 (oopps, just dated myself)....

Thanks for the coments about the photo site, displaying one's
sickness to the public can be fun....... :roll: :lol:
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