my advise has to be sell the lot and start over im afraid
if you engine is 90 spec you will have a hole in the block going thru to the flywheel
which helps as you can fit an efi flywheel and cps (in the hole) and use your bottom end but by the time you do taht you will put about £50 into a headset and bolts that could have bought you a zetec bottom end then you will still need an efi head unless you want to spend about than the cost of an efi head on adapters (which could mean the inlet hits things)