I do my own it is a copy of and old B&M Manual Pack and they do not make it anymore to bad it was a great working kit. I have built several of them for myself and others it is not to hard once you do it a few times. You can ask Gregaust what he thought of the plans I put together for him I think he built one, I am just not sure if he ever used it or not.
what modifications are necessary to convert from automatic-to-manual control of the transmission? I've looked at both the manual and a stock valvebody and cant see any difference, but then again, I really didnt look that close.
Most of the mods are in the channel plate. The manual valve bodies I have form ATI and TCI have only half on the valves in the one one of the valves is blocked in place and the chanel plates are modified. They actually look real easy to duplicate the mods. I have thought about sitting down and trying it.
to convert a stock C4 valve body to manual Per B&M Manual Pack, requires that several holes in the seperator plate be welded shut and then there are several new ones that need to be drilled to make copy of original B&M part. Then there are several places on the upper and lower halves of the valve body that require drilling to remove parts of the walls between passages so that fluid is transfered to other passages. There are several of the spool valves that are blocked in place so that they no longer move and then there are some stiffer springs that should be used, but most that I have done could use the stock ones and worked fine. this is a over simplified explaination of what is done to the stock parts, but the basics are here.
Years ago, I made some copiues of the Fairbanks manual VB for a C6. It wasn't a difficult process to duplicate.
The Fairbank's people used round rod to change the passages in the VB. They used an end mill to bore a hole and then JB welded the rod into place. I was able to accomplish the same thing with my drill press and an end mill.
The seperator plate was the hardest part. By that, i mean getting the hole the right size.
It can be done, if you have one to copy and the patience to do it.
come to think of it, I think I might have a fairbanks manual vb out in the shed. I'm gonna go pull it out of the trans after work, and see what the differences are. I've got my buddies 64 Falcon sprint here with trans troubles, and it needs to have a manual vb installed. I figured if I can duplicate one, it would help him out.