new engine and gearbox

[Sv6 Commodore :)]

I have heard from a mechanic that somewhere on this site i can buy a new gearbox and engine dirt cheap can someone point me in the right direction? also are these engines and gearboxs worth the time or just a waste of money?

[henrytad]

its possible, sometimes they come up when people are wrecking their cars in the parts for sale forum. does take time and youll need skill and equipment so it depends why you wanna change it?
i thought about converting my vz V6 to a V8 LS2 but in the end its not just the engine, theres the gearbox, breaks, computers, exhaust etcc.