zetec turbo -

I have done two - one was a 'ye olde back street jobbe' - milled , heat treated pistons to lower compression £100 1.6mm head gasket£45 , heat treated and peen shotted conrods £150 , arp bolts all round, uprated valve springs - 250bhp max

other was - a fully forged pro built engine everything except exhaust cam with hybrid gt25 410 at sabre

many options - best bet would be to look out for second hand focus rs mk1 pistons and rods uprated valve springs from st170 and ur good to go

obviously u will need injectors and ecu to suit aswell as turbo but that can be from escort rs turbo etc , inlet again - efi..many options