The only thing I would like to add is that if you use an older case and then use the electronic lock-up with the solenoid then wont the case still need to be modified for the lock-up solenoid wire ? I remeber the simple lock-up trans that use just the one feed wire that came in near the back of the trans looked to be a round hole in the case. And I think they were all the 904 style. Course the later ones with overdrive had the three wire oval plug and the the newer ones with electronic gov had the bigger hole for the extra wires. I am just thinking to myself the case would need modifying for the lock-up wire or wires if it was done with the electronic lock-up. Ron

Ok - so for those that really want to convert an old 727 to lockup here is how it is done. Take a good operational 727 with lockup - remove the input shaft and rear clutch piston retainer, reaction shaft support, valve body, converter from a good functional lockup 727. I suggest you retain the matching front clutch retainer with the reaction shaft support to avoid mismatching as there are two front clutch drum bushing widths - narrow (early) and wide (late). You also need to be careful about the interface from the input shaft to the output shaft at the number three thrust washer. There are changes there that you need to be aware of - all else fails - transfer the output shaft from the L/U trans to your old 727. If you decide to use the early lockup valve body with lockup module - check and clearance the case to prevent interference. The only benefit of using this design instead of the electric lockup is no wiring is necessary. But in order to raise lockup speed and prevent droning - you need to increase spring pressure in that lockup module. This was a service fix but the production springs only get you some relief. Using the electric lockup valve body allows you to control when and if you get lockup. If you decide to use the electric lockup valve body you need to drill and tap the case to accept the bulkhead connector - just like you do when you install a Turbo-Action Transbrake. If you check cooler line pressure with a gauge - when you get lockup you will get a rise in cooler line pressure of 5 - 15 lbs. Converters run cooler in lockup for obvious reasons - little to no slippage. Cooler line return feeds the geartrain inside the trans - so cooler fluid to the geartrain makes them last longer. Like I stated in an earlier post - most of the converter failures were on old design lockup converters - we changed the piston design in early 2001 time frame - this reduced if not eliminated most all converter failures in regards to the lockup disc. You can still get stator ORC failures and bearing failures but most of the issue was the disc failing. RWD lockup is slightly different than FWD - on RWD we send fluid in to the converter through the input shaft drilled passage. To get lockup we shut that flow off - now all the fluid pressure and volume entering the converter is on the backside (apply side) of the lockup piston. With fluid flow down the input shaft - we have fluid pressure on the off side keeping the converter off. Ever wonder why some lockup transmissions stall the engine when you put them in gear? No flow to the off side - usually due to the converter switch valve being stuck on due to debris. There are other reasons for this stalling as well. As for the early design sucking - depends how the vehicle was driven. If you get in the vehicle and get up to 45 or higher MPH and drive at or above this speed there are generally no complaints. If you drive at this low speed you get that droning noise. This is engine firing through the powertrain, not the converter's fault. Think manual trans in 4th gear at about 20 or 30 mpg and you open the throttle - you get the same droning. This can be resolved sometimes by damper spring changes but you give up durability if you make it weak, same as the spring damper assy. in a manual trans clutch disc assy.