I am getting ready to build a doubler and had a few questions. I have the Range box from the 203 still connected to the t350 transmission. I am still looking for a 205, but I was curious about the specifics, does the 205 need to be previously mated to a specific tranny? Any info would help alot. Thanks again.
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
Building the DOUBLER
- Thread starter hoff83K5
- Start date
CDA 455
3/4 ton status
tlspeed
Registered Member
Specifically you are looking for a np205 off of a turbo 400. These have the large bearing and 32 spline female input. Finding this case may cost some coin though.
There are ways around this that could be cheaper if you dont mind tearing your case apart. You can source a case from a 4 speed or th350 and buy a input for a th400 np205. Then dissasemble the 4 speed/th350 case and have the input hole machined for the big bearing and larger input. Disadvantages is you still have a the weaker front output on th350/4 speed case.
Another option is to do what i did. Buy a Ford married np205 easily had for $100 or so. and dissasemble it saving all the internals. Then take a 4speed np205 (readily avaiable for cheap) and diassemble this and throw all the internals except the shift forks.
Then have this case machined for the large bearing input and resassemble with the ford parts. You will now have the heavy 31 spline female input (must specify ford input shaft when doing doubler as it is different spline than GM) You will also have the strong 32 spline outputs all the way around.
Just my .02 cents
There are ways around this that could be cheaper if you dont mind tearing your case apart. You can source a case from a 4 speed or th350 and buy a input for a th400 np205. Then dissasemble the 4 speed/th350 case and have the input hole machined for the big bearing and larger input. Disadvantages is you still have a the weaker front output on th350/4 speed case.
Another option is to do what i did. Buy a Ford married np205 easily had for $100 or so. and dissasemble it saving all the internals. Then take a 4speed np205 (readily avaiable for cheap) and diassemble this and throw all the internals except the shift forks.
Then have this case machined for the large bearing input and resassemble with the ford parts. You will now have the heavy 31 spline female input (must specify ford input shaft when doing doubler as it is different spline than GM) You will also have the strong 32 spline outputs all the way around.
Just my .02 cents
If you do look for a th400 version np205, The round bolt pattern style found in 1985 and up trucks will have a long style input shaft. This won't work for most doubler kits. Sumner machine is the only one who makes a kit that will work with the long input. So you either need a figure-8 style np205 that has a short input, or if you get the round-pattern you must swap out the input for a short version.
