You could get the same with a good pinto head and cam mind.
Aspirated cossie done properly is fuckin rapid, but the head is the cheap bit!
Forged pistons and cossie rods for over 7500 rpm, otherwise you need to have valve cut outs in your pistons in case of any bounce or if using wilder cams - non turbo cams definitely recommended...
There's a book on it, got mine from burton power, guy seems to know his stuff - it's a shitload better than any XE lump anyways, and is mucho easier to fit!