Howdy, I know this has been covered before but I can't seem to put the information together on doing this. Starting conditions, 61 364 Nailhead with dynaflow, 66 SP400 from a Riviera. I'm going floor shift with Wildcat console and shifter so ignore that stuff. What does it take to physically get the SP400 working behind the 364? I know there needs to be a spacer for the crank pilot hole and that the flexplates don't match up. Is it possible to get the flexplate to work without machining the crank? Thanks,
You need the TH400 flexplate, cut off the flange on the rear of the crank to make it flat. An adapter for the crank. Adapts the pilot of the TH400 converter (smaller) to the larger DynaFlow pilot hole in the end of the crank & also support for the smaller hole in the flexplate. DO NOT ENLARGE the flexplate hole to fit over the end of the crank, it weakens the flexplate considerably. Also a 364 engine has an imbalance of about 3 1/2 ounces as oppossed to a TH400 NailHead flexplate of about 4 1/2 ounces. If you don't remove about 1 ounce of this weight from the weighted part of the flexplate your engine will vibrate badly because of being out of balance. Also if you don't line up the index holes between the crank & the flexplate the engine will vibrate badly. The flexplate & crank bolt holes are all the same spacing, meaning the flexplate can go on 6 different ways. A crossmember from the donor car made to fit. You may be able to modify yours. The yoke for the rear of the trans & you may have to have the driveshaft shortened. The yoke will fit your driveshaft. If the yoke can't be found, they are getting very difficult to find good used & are not available new. If you can't find a yoke you can get the tail housing off of a newer TH400, it bolts on, & then you can buy a new yoke. Don't forget to wire up the neutral safety/backup light switch. Should have come as a complete assembly with the console. Oh, also the starter from the donor car or one of my mini-starters for the NailHead.
Ouch... I think I'll just get the adaptor and run a later model TH400 or the eventual TH200-4R in there instead of messing around with all that for a temporary transmission.
You will have to do most of the same anyway whatever trans. you may end up using. If this is too much work for you I would reconsider about doing anything in the 1st. place as this is not a lot of work. It's just lenghty to explain rather than do if you have some experience.
Cutting off the end of the crank, no mater how simple it is to do is a lot of work for me. I did not check the instructions however for the NW Speed adapter kit to see if this is required.
its not the work required or time, its the step of permanantly altering the crank that makes it a lot of work to me. There are no instructions for the adapter ring on the NW Speed kit but I've seen others with year dependent kits. I really don't want to take the dynaflow on powertour but if modifying the crank irreperably it what it takes to put anything else in there... I might just take it. Thanks for the help Tom and thank you for your continued support of the nailhead community,
Tom, we have spoke of this before on another forum. Who has a adapter to do this. My application would be from a 65 sp400 to a 59 401. Will the adapter have to be custom made or is there a source for this? TP
