1959 open diferential swap questions

[finsnchrome]

Hello everyone, I have decided to swap from a closed to open driveshaft in my 59 electra 225. I know this topic has been beat to a certain extent, but please bare with me as I am actually going to make this happen, and not asking theoretical maybes.

 

Question 1,  Does anyone know if my 59 engine will mate up to a 63 dynaflow without any issues? Im talking strictly engine to trans.

 

Question 2, I have a 63 wildcat rear end which is 61" hub to hub, compared to the buicks 60" can i make this difference up on wheel offset, or is recommended to cut the rear end 1/2 on each side?

 

thanks

[RivNut]

Question 1) The trans will bolt to the block.  You'd need to compare the flex plates and the crank hubs.

 

Question 2)  Do you think a 1/2 inch difference on each side will cause clearance problems?  How much room do you have now between the fender and the tire?

 

Does you 59 have the optional triple turbine Dynaflow or the twin turbine Dynaflow? If it's the twin, I think the swap is an R&R.  Could you just r&r the torque ball tailshaft for a u-joint type tailshafts on your current transmission?

 

Edited September 10, 2017 by RivNut (see edit history)

[finsnchrome]

On 9/10/2017 at 11:45 AM, RivNut said:

Question 1) The trans will bolt to the block.  You'd need to compare the flex plates and the crank hubs.

 

Question 2)  Do you think a 1/2 inch difference on each side will cause clearance problems?  How much room do you have now between the fender and the tire?

 

Does you 59 have the optional triple turbine Dynaflow or the twin turbine Dynaflow? If it's the twin, I think the swap is an R&R.  Could you just r&r the torque ball tailshaft for a u-joint type tailshafts on your current transmission?

 Thanks for your reply.  It seems I have about 3 inches of clearance either way, buI wanted to ask in case anyone was an expert and knew of issues that I may not be aware of.     I have the twin turbine dynaflow, however, it will need a rebuild, and the 63 dynaflow with the u joint type tailshaft is rebuild.  But now you brought up a good point.

I wonder if the tailshaft is interchangeable because if so, it would save me a lot of downtime while i prep the rear end and gather parts. 

[RivNut]

If the 63 Dynaflow has been rebuilt, I'd go that way.  You'd probably have to drop the tranny any way to swap tail shafts, so just go with yhe rebuilt one.  If you're going to an open drive shafts, have you considered going to a three speed Turbo Hydro 400? That would take some work, but I guess it depends on what you're after. 

 

Ed

[finsnchrome]

I have considered the TH400, but since I am on a budget, id rather do this in stages, to keep the car operational as much as possible

first id like to do the open driveshaft and rear end, with airbags, then have a th400 built, and eventually buy an ls3 and install those 2 together.   that would make a reliable car that matches the torque of the nailhead

[NTX5467]

 

 

One of our chapter members had the THM400 swap done to his '62 LeSabre.  The difference was very significant!  So much that his then-teenaged son wanted to drive the car all the time (not!).  As good as the DynaFlow or TripleTurbine variation might have been, that additional low gear does make a difference.  Probably like the comparison between a PowerGlide and a THM400 '65 Impala, or a more modern pickup with the 6-speed 6L90E and the old 3-speed automatics.  

 

Even in manual "L" with the DynaFlow, you've got the 1.8 (approx.) geared gear ratio, plus the torque multiplication of probably about 2.5, then the rear axle ratio.  With the THM400, it's 2.48 (gear) x 2.2 (torque converter x rear axle ratio.  With the 6L90E family (and most every other modern 6-9 speed automatic trans), it's 4.5 (approx.) 1st gear x 2.0 (approx.) torque converter x rear axle.  Interestingly, the 2nd gear in the 6L90E family approximates 2.48, so if you have one of these later model vehicles, put the manual shifter in "M" and select "2" and start from a stop.  quite a difference from starting in "1".  So, the more gears and the greater the low gear multiplication might be is very noticeable.

 

As many Riv owners seem to like the THM200-4R conversion, with that trans family taking less horsepower to run, a modified/upgraded THM200-4 might be a better option.  Only thing is that the instrument panel shift quadrant might not work as well with such a conversion.

 

NTX5467

[finsnchrome]

14 hours ago, NTX5467 said:

 

 

One of our chapter members had the THM400 swap done to his '62 LeSabre.  The difference was very significant!  So much that his then-teenaged son wanted to drive the car all the time (not!).  As good as the DynaFlow or TripleTurbine variation might have been, that additional low gear does make a difference.  Probably like the comparison between a PowerGlide and a THM400 '65 Impala, or a more modern pickup with the 6-speed 6L90E and the old 3-speed automatics.  

 

Even in manual "L" with the DynaFlow, you've got the 1.8 (approx.) geared gear ratio, plus the torque multiplication of probably about 2.5, then the rear axle ratio.  With the THM400, it's 2.48 (gear) x 2.2 (torque converter x rear axle ratio.  With the 6L90E family (and most every other modern 6-9 speed automatic trans), it's 4.5 (approx.) 1st gear x 2.0 (approx.) torque converter x rear axle.  Interestingly, the 2nd gear in the 6L90E family approximates 2.48, so if you have one of these later model vehicles, put the manual shifter in "M" and select "2" and start from a stop.  quite a difference from starting in "1".  So, the more gears and the greater the low gear multiplication might be is very noticeable.

 

As many Riv owners seem to like the THM200-4R conversion, with that trans family taking less horsepower to run, a modified/upgraded THM200-4 might be a better option.  Only thing is that the instrument panel shift quadrant might not work as well with such a conversion.

 

NTX5467

Its looking like I will go the thm400 route in the future....  Would you happen to know if i could switch the tailshaft of my 59 transmission with the 63 one? Since the 63 is rebuilt it would be nice to be able to swap them, and drive the car while I get a new engine thm400 and rear end/4 link sorted out

[NTX5467]

No idea about the tailshaft housing.  Sorry.

 

NTX5467