164 vented on 144 , machine up 2 of each 19mm & 22mm tunes and buy new 8.8 bolts and inch longer than standard lower wishbone bolts then use existing shims to give 3 degrees of neg camber.
Remove all body deadener, you'll be amazed how much there's in weight.
What year is your 142.
Start out as this
Daniel Spranges 142
Fuel surge tank , 4lb Mazda pump from fuel tank to surge tank , 2nd 4lb Mazda pump from wreckers from surge tank to carby's and return to surge tank which also returns to tank.
Surge tank is a small fire extinguisher ( its a pressure vessel) so is allowed , tipped up side down , drilled and pipes welded in place.
If your 142 is injected even better as a return loop fuel lines will already be there , just need small modifications.
If you've got the early 142 you may be asked to put a fire wall in where the up right back seat goes as I had to at Oran Park many years ago.
Depending on how serious your going to get a CAMS manual will tell you legal reqiurements forbiulding cars etc , they have just changed the window net rules in the last 2 weeks.
Start on a set of nearly worn out Bridgestone 003 or similar type of tyre to save money while rebuilding suspension , then worry about expensive soft compound race tyres.
Don't lower the car more than 25mm/1" as you put the shock piston to far of centre , give Ash at DVS a call he may have something second hand available
Warick Ahearns 142 sport sedan a well biult well driven race car , all motor sport is fun and a great journey.
Note: buy a duel axle car trailer and use the tyres on it as wets , saves alot on storage and carrying rims & tyres.
Early Holden, eg Hg, Hk etc are same stud pattern , so easy way to go larger 15" rims or bigger.