Putting this here, for safe-keeping also. Random info... Atc70 engine cases are pretty much the same as ct70 cases of similar years. Atc70 engines are all 6v. 6v cases CAN be used to convert to 12v, but you have to cut a small notch out of the left side case for the trigger mount of the stator plate. ATC70's are 3speed semi-auto's until mid 1982, they became 4down 4 speed semi-auto's. In 1985 they changed the shift pattern...4up semi-auto. In 1986, 3 wheelers were outlawed and the TRX70 4 wheeler was born. They were made only in 86 and 87. They are 4up semi-auto's, like the prior ATC's, BUT...the stator changed to ?, not sure what exactly...and the engine cases changed to GB4 12v type engine cases. The TRX70's are all 4speed semi-auto's in 12v cases. They have a 12v type crankshaft too. ATC70 and TRX70 cases...and engines, can usually be had for cheap on eBay. They are a good choice to build engines for CT's and Z's. Kickstarter's can be added, you just need to use a clutch side cover that has the kickshaft hole...or drill/mill the hole in the Atc70 side cover. Then use the correct pinion gear on the kickshaft...depending on the transmission used.