Reply to "What was the Original Carburettor used on the 1984 GT5"

As a US GT5 the car may have been equipped with the Auto Exotica/Amerisport (Kirk Evans) induction and emissions system which included a Holley "street Dominator" single plane intake manifold (#300-12) and a Holley list #8005 carburetor. If so equipped it would have also included headers equipped with catalytic converters and a "box-shaped" dual snorkel air cleaner assembly. Most owners removed those items long ago, and you probably wouldn't want to re-install them. I've only seen one GT5-S here in the US which still had that equipment installed.

You would probably want to use which ever manifold and carburetor De Tomaso was installing on the European versions. During the 1970s De Tomaso installed Holley list #4777 carburetors (650 CFM, mechanical secondary, center hung fuel bowls, double accelerator pumps). I'm not sure what was being installed in 1984. Perhaps some European owners will help you out with that info. Or perhaps Peter Havlik can help ... Peter?

Since you're in Australia, the "square bore" iron intake manifold from an early 351 GT plus the Autolite 4300A carburetor (630 CFM) would be an authentic induction system, if not OEM. Or perhaps an Edelbrock #2750 dual plane manifold with a 650 CFM or 750 CFM carburetor tuned for "street performance" and equipped with center hung fuel bowls, electric choke, and annular booster venturis would fit the bill. Once equipped with the proper Australian air cleaner assembly nobody will know what's underneath, nor shall it be a major concern so long as it is of good specification, good quality, and performs well.

Here's some carburetor suggestions:

Vacuum Secondary Carburetors
650 FFM - Demon #1282020VE
750 CFM - Demon #1402020VE

Mechanical Secondary Carburetors
650 CFM - Demon #1282020 equipped with electric choke kit #421440
650 CFM - Quick Fuel #SS-650-AN
750 CFM - Demon #1402020 equipped with electric choke kit #421440
750 CFM - Quick Fuel #SS-750-AN

Good luck with your new car!