Ya, I pretty much agree with the other guys!.. I have never had a turbo car, but i have had few supercharged 2v 4.6 stangs with forged internals to handle upwards of 800 hp or so.. I've had 2 procharger kits started with the p1sc unit and after bout 7-8 months top it out and needed something else and went with the d1sc unit and car dynoed at 682 rear wheel on race gas, 75mm tb and trickflow ported plenum, professional products racer/competition manifold, high flow fuel rail kit, stage 2 ported n polished heads custom, ford gt-40 duel fuel pumps, boosta-pump, etc and on that setup it dyno'd at 758 rear wheel horse. But in your case since u just wanna leave the engine alone and run on stock pistons n rods why not go with a Procharger p1sc kit or
Vortech ( can't think of their models brain fart ) but the smaller one's and if you don't have the supporting parts like fuel injectors, Kenne Bell boosta-pump, air fuel, boost psi gauges, with the blowers in question fuel inectors ford cobra 39pd blue tops, 42pd ford green tops and if u want to be really secure go with 60pd fuel injectors but you'd be set with 42pd ford green tops plus the boosta-pump. I think your year cobras can handle round 400 to 450 max rear wheel horsepower before they blow up!.. You could look online, go to a junk yard, or even ebay and pick up a bare Teksid aluminum block and start building it up get a set of forged rods when you can afford it, then again when u have the money buy the next thing n so on n so on.. that way u have some security/backup incase or i should the time comes that it goes pop!.. lol . When your having it dyno tuned and they set it at max boost with everything i said to get u should be rite at that breaking point/edge!..