I agree with above although as far as a guesstimate would be --I wouldn't go to far north of what it is stock....heads and cam is the crucial point but also those gears have to go..
I had an aquaintence of mine tell me that he could beat my stang when it was still stock with his 428 Pontiac 69 Firebird...well maybe-went to the track and I clicked off a 13.9 with gears,exhaust and pullies to his 14.8 and his 2.** whatever gears..he'd kick me in top end,but on the street -forget it....
sorry I rambled--gears..thats the ticket for a low buget start...forget the cam-if the heads ain't flowing then its a bottle neck...