Ive done it a few time now.

All you reaaly need is carbs, manfifold, bike pump or pressure reducer and an ignition system such as megajolt or any of the well known brands as it only controls spark

Problems to over come would be emmissions for mot and the pats on an escort or focus

Heres mine in a mk3 fiesta zx9r carbs, alloy inlet, megajolt and R1 carbs

Goes well and sounds amazing