Suspension, sway bars, wheel&tire upgrades, help!!!

hello and welcome from the uk, i have a 68 barracuda 440ci and manual so loooota weight,in my opinion suspention upgrades benefit with additional weight loss, heres what i have so far as i intend to use on track and no straight line doings, 1.18 torsion bars,magnum force tubular uca,strut rods,hellwig sway bar,poly bushes,monroe shox<soon to be spax> flaming river manual steering box,rebuilt colum,battery in trunk,ali inlet/rad/water pump,fiberglass bonnet and wings< 40kg saving just on that> i beefed up my rear springs with a leaf from a fiat ducato van!!! however when funds allow will replace,anyone who says a big block wont handle right never seen me fighting at the wheel! my car went from a death trap 318 barge that lookes like some oil tanker on the high seas to a pretty shap point and go giggle car,just takes the right ingrediants............oh and went with rocket fuel 15" with avon zz3 tyres all round, 225x60 x15, keep same size front to back, 18s look good but in my opinion wont handle anywhere near.i have done this over many years,its always wet here and i have no garage to work in plus i get raped by import duties so its going to be cheeper for you! i reakon im getting there slowly, there is a chap on here autoxcuda and there are video links to him in his cuda on the track, onboard camers, no body roll that i can see, very inspiring as before i saw the vid was at a turning point and it spurred me on no end! good luck, just do a bit at a time and have fun, drive safe