no need to go through all that trouble. the factory gearbox could be used. just swap out the piston bell housing and use the rx7 bell housing

But the rex bellhousing still has the slave cylinder on the top

yes, and? you swap the second gen. oil pan and put a 13B gsl-se oil pan with a 12A or 13B gsl-se timing cover and lower the engine and make the front engine mount. when the old style 13b oil pan is used, you have tons of clearance. I have done tons of these trucks.. plus i had a turbo charged 13B truck. insanely fast..

Except that the piston engine input shaft is 1/2" longer than the rotary one and will need to be cut down, or a spacer added between the block and bellhousing.

yes..........and dont forget the piston gearbox is way stronger. its a 2 ton truck

USE THE FACTORY GEARBOX CROSSMEMEBER MOVE IT FORWARD TO THE NEXT HOLE IN THE CHASSIS, UNSTITCH THE FACTORY MOUNTS AND MOVE FORWARD, FABRICATE A FRONT BRACKET, AND TAKE A 5MM NOTCH OUT OF THE SUPPORT BRACKET BETWEEN CHASSIS RAILS. USE A EARLY 13B SUMP AND A 12A FRONT COVER TO FRONT MOUNT THE MOTOR AND A SERIES 4 RX7 GEARBOX. SPEEDO CABLE FITS STRAIGHT IN. THE TUNNEL JUST NEEDS A BIT OF A LOVE TAP TO ACCOMODATE SLAVE CYLINDER. EASY AS CONVERSION IF YOU CAN WELD.

Re: B2000 Rotary Swap need help
 

how can i use the factory ecu from a 13b