Nikasil linered block £2.5k
lightweight crank £1k
wrc long rod £750
cosworth race pistons short skirt(or similar)£650

worked head from a good cast £1200

new springs£150

a pair of cams to spec £320

tubular manifold £900

bw turbo s300 to spec £1100

tial w/g £450

hart inlet plenum or similar £400

big injectors to suit £300

decent management and engine loom £2200

long studs and nuts £150

gaskets sundries etc £500_£600

labour to assemble and the bench dyno £1500

there will be other odds and ends but thats about right and should be good for the right hp

so yes imo easily achieved these days for around the £15k or below mark!!

God knows where £35k is coming from???

Of course you could spend more and go even further with alloy blocks and or 2.2 bottom ends and silly priced long studs and inlet plenums etc but i think most tuners would be happy to build an engine to the above spec and get circa 600-650 hp for £15 k...?

As said its not as hard as once believed to get big power now days..

500 hp now literally is a well built long studded 200 blocked engine with a decent blower a good inlet cam and a half decent inlet plenum!! back in the day tuners did everything they could to get over 500 hp at a massive cost and it still was nothing like todays spool and lb ft to drive..