As to whether it would be streetable, that depends on the donk, if it needs to be really cammy and reving its tits off to make 300hp it might make for a painful daily driver but if its doing it in a relaxed fashion like say a 426 Hemi would then it would be a joy on the street, I dont know what times a 700kg car would do with 300hp but it would be beating everything else on the road off at the traffic lights.