63 Riv....Dynaflow to ST400 swap????????

[Michael_in_WA]

Hello,
I just bought a 63 Riv with a 401/dynaflow. It needs engine work. For time and budget reasons, I am considering using the low mileage 401/ST400 out of my 64 Electra, but will this work??? If this will take a lot of midifications, then I don't want to do it. Also, correct me if I am wrong....I cannot use my 64 401 with the 63 Dynaflow because of a different bolt pattern on the crankshaft flange....right??????
Thanks in advance.

Michael S.
1963 Riviera
1965 Special
1966 Skylark
1980 Riviera
1984 Riviera

[theoldguy]

It is not the bolt pattern that is different, it is the flange itself. The flange is machined for convertor clearance and they will not interchange without some machine work.

[Dr. Frankenbuick]

Michael,

I'm not sure there is enough metal on the 64+ crank castings to safely increase the size of countersunk hole in the crank to accept the larger Dynaflow converter snout.

Your 63 engine will accept the ST 400 trans with a bushing (Carmen Faso - (716)693-4090) in the crank to support the converter, and machining the center hole of the 64+ flexplate larger to fit the 63 crank. All bets are off on the engine balance though. The 63 and earlier flexplate is just that. A triangular plate with no ring gear (Dynaflows have the ring gear on the converter). It will not fit the ST 400 trans no matter what you do, and the flexplate for the ST 400 will not fit the Dynaflow converter.

A complete 401/ST 400 set up would be easier to swap into the 63 Riv then making the changes necessary for the 63 engine/64 Trans set-up. Your 64 401/ST 400 combination will fit in the 63 Riv using the driveshaft (complete with yoke), trans cross-msmber, trans mount and shift (downshift as well) apparatus all from a 64 or 65 Riv. I started a ST 400 swap in my 63 Riv about 15 years ago when my Dynaflow quit. I got all the parts from a 65 Riv to make the change, but I gave up after meeting up with the converter/flexplate issue concerning the 63 engine /64 trans described above. I just had the Dynaflow rebuilt instead. I recall you will have to do some welding or put some new boltholes in the frame for the 65 trans cross-member, but it was a long time ago. Have at it!


------------------
Steve B.
GSCA #2173 (1986)
67 GS 525 Stg IV
66 GS Convertible
65 GS HT
63 Riv

[This message has been edited by Dr. Frankenbuick (edited 06-09-2002).]

[Michael_in_WA]

Thank you Steve and "the old guy" Based on the information you provided, I have decided to stick with "stock". And, coincidentally today after reading your posts, I found a buyer for my 1964 401/ST400.
Again...Thanks,
Michael