Okay, if it's cheap then you can afford the insurance...
SX Owners Club.
From other posts, you're wanting to put something lower powered in there and benefit from lower insurance?
Yes, it's true that some insurance companies establish a basic insurance premium by considering the donor vehicle. So if you are, for example, transplanting a 1.8 into a Ka you might be better off using the 1.8 from the Mondeo and not from the Fiesta XR2i.
But that's just the starting place, they then load everything up.
You need to talk to some insurance companies, avoiding those that use bad breath sneaky pants tactics, to find out what it would cost.
Some of the Puma boys swapped their wonderful, delicious, sweet, revvy 1.7 Zetec-SE for a 1.6 CVH and ran this for a few months before turbocharging it (what an expensive way of doing it!) and their insurance went up...