jeff wood

Hi guys, I've got an 07 YZ125 which is I use for occasional motocross, nothing serious just fun on practice days.. But I want to start doing a bit of green laning. I'm in the process or road registering the YZ, but, I know that that the YZ motor isn't really suitable for green laning. So, I just wondered, how easy or hard would it be to stick a DT125 engine in, just for green laning, (Idea being that I could put the YZ motor back for when I want to use it for MX). Now I know that at this point people will just be saying, why not just buy a DT ? Well, firstly, I already own the YZ, secondly, the YZ chassis is of course a lot better than a DT, it's much lighter, much better suspension, (which Ive just had set up for my weight), and I've a lot on my YZ making it look brand new. So, if it's an easy job, then I think it makes a lot of sense. I know it wont have the same performance, but I'm not bothered about that, the sort of trails I'd be going on are quite easy, nothing too demanding. So, has anyone on here done this conversion ? Are the engine cases the same ? Will it bolt straight in, or will brackets need to be made ? What about the CDI I assume I'd need the DT one ? Thanks in advance .. Jeff.