I have found that the best way to fit this engine is through the bottom after removing the cross-member and the anti-roll bar; this method will allow the gearbox to drop down and makes an easy job of bolting up the bell housing.
Once the engine is bolted to the bell-housing take the time to fit up your exhaust down pipes, you will need to use the flanges from the 24v and weld them to your old down pipes (believe me its easier this way),but if you do not fancey doing the welding,you could contact TOP BOSS (on links page)as they can supply you new tubular down pipes.
The tubular down pipes will also give you slightly more power so its worth while going this route.
When fitting this engine you might end up with no skin on your
knuckles.
you can also notice that the standard XR4x4 throttle cable matches up with the cosworth linkage
1. It keeps the oil temp down
2. It makes life easy with oil filter changes(as seen below)