Recently my belts snapped on my 340, but i have a donor car 360 with a 5-spd manual, does that gearbox go on the B14?

You will need a bellhousing, prop and gearbox from a 1.4, the prop and gearbox are the same for 1.4 and 1.7 however the 360 one will only work with the Volvo engine

300 series engines do not bolt onto their gearboxes.

The 360 uses a torque tube between the gearbox and the Volvo engine, the 340 1.4 Renault Engine does not. The 340 gearbox is bolted to the chassis and not the engine. Only the prop connects the 340 gearbox to the engine.

The front of the 360 gearbox requires the torque tube to support the gearbox, the 340 gearbox is different at the front to have mountings to the body.

In short no, not without alot of adaptation/conversion