Model Monaro GTS Coupe – Model No. 80837
Build date 1-Nov-72
Delivery date 14 November 1872
Delivery dealer Claridge Motors, Unley, South Australia
Paint colour Nutmeg Metallic  –> paint code 567 – 13886
Interior trim Black  –>  trim code 1844 – 10X
Photos 1972 – 1975
1976 – 1990
1991 – 2000
2002 – 2019
2020 to present

Early history

This car was completed on 1st November 1972 at Holden’s Dandenong plant.  This car was built to my order so that a unique combination of options could be obtained.   It took nearly 3 months from order to delivery.

Unfortunately, there was no way I could afford the purchase price of my dreamed-about GTS 350 which at the time cost approx $4,700.  Comprehensive insurance on a GTS350 for a then 19 year old was prohibitive and fuel costs, even at $0.15 per litre for a high fuel consumption daily driver could not be funded along with loan repayments from my then wage of around $50 per week.  So I squeezed the budget just above the base GTS 253 manual and optioned the M21 “High Performance” 4 speed (+$35), a Limited Slip Diff (+$45) and dual exhausts (+$60), heavy duty springs ($10) and ER7014 redwall radials ($20).  All up $3,915 plus rego and insurance.  Could not afford the Holden radio at $100 or any other desirable option.  But I had my new Monaro GTS Coupe.

The GTS was funded by;

  • savings of $1,000
  • a bank loan (7 year term !!) of $2,500 only if my father was guarantor
  • $500 trade-in on my 1966 Cortina
  • $100 fleet discount when bought through the company my father worked for

The car was initially registered in my mother’s name because only wives of company managers were eligible for the company’s fleet discount scheme and also it was the only way I could get comprehensively insurance as not the primary but a “designated driver” although that still meant an horrendous excess.

Not being able to afford the GTS350 back then has cost me much, much more ever since as I have done multiple engine upgrades to the car and bought and restored a Monaro LS350.  With the wisdom of hindsight, I should have waited until May 1973 then ordered a fully optioned, new GTS 350 with the last of the 4 speed Muncie transmissions, in one of the many spectacular colours then available.

My Monaro was a daily driver and main family car from 1972 until 1991.  Seeking higher performance, in 1979 I replaced the original 253 V8, at 160,000km with a new 308 V8 “crate motor” from GM Parts & Accessories.  No thought was given to losing the original engine which I sold to a wrecking yard for $350. The new 308 delivered considerable improvement in power with a commensurate reduction in fuel economy !!!  Various other “factory” options were added over the years, these included power steering, factory air conditioning, tinted side glass and a power aerial.  In 1981, the M21 was replaced with a Trimatic auto to make family driving in the city a little easier.

In 1991 it was de-registered and kept in storage until 2001.  The motor was started every week with regular oil changes even though not driven.

After visiting the second Monaro Nationals at Wangaratta in 2000, I was motivated to get my coupe back on the road and join the Monaro Club of Victoria.  In 2001, it was brought back to roadworthy condition by replacing front suspension bushes for the 1st time, replacement of brake components, radiator hoses and drive belts.  The M21 was re-installed.  The coupe still has its original paint and interior trim.  It passed roadworthy on 4th October 2001 and was fitted with personalised Victorian number plates with the same letter – number combination as its original SA plates – RPX-990.

“Factory 350” engine transplant

In June 2006, the 308 V8 and M21 combination was replaced with a standard “factory” HQ 350 V8 and Turbo Hydramatic 400 drivetrain taken out of an unmolested 1973 Statesman Deville 350.

The Statesman engine was totally original – all special clips, brackets, heat shields, ADR-27A pollution gear were all still in place.  The engine appeared never to have been reconditioned and cylinder compressions were all above 150 PSI so reconditioning was put off to another day.  Every oil seal was leaking so all were replaced including welch plugs.  The heads were not removed.

The Rochester Quadrajet was disassembled, cleaned and new gaskets installed.  When the engine was finally dyno-tuned, the Qjet throttle body was found to be warped from overtightening its 4 mounting bolts over the years and required straightening.  The throttle shafts needed to be re-bushed.  Interestingly, the original factory spec primary jets and secondary metering rods were still in place.  Both were changed during the dyno runs to achieve optimal power / economy.  The original Delco points distributor needed a replacement shaft due to wear of the original.  The camshaft was rated as moderately worn but still good enough.

Following the dynotune, performance improvement was very evident throughout the rev range.  The previous very brief “chip” from the back wheel spin at the 1 – 2 shift was now much more “vibrant”

I used the same exhaust shop as I had for the LS 350 dual exhaust system.  They are able to bend up a set of engine pipes from a single length of tube without joins as per the factory spec including the cross-over tube.  A new exhaust heat valve (still available in the US) was installed that closes off the RHS exhaust outlet and forces the hot exhaust gas back through the inlet manifold to increase cold start fuel vaporisation.  These valves are almost always missing from surviving 350s but they work fine and are fully open once the engine reaches operating temperature.

“385 Fastburn” engine transplant

After 2 years of regular driving, it became clear that the Statesman 350 engine was very tired and needed to be reconditioned – for the first time!   Instead, I decided to sell it as a complete factory engine with all its original accessories, but in need of reconditioning and purchased a new crate motor.   In October 2008 a GM Performance Products “385 Fastburn” engine was installed and coupled to the original, un-reconditioned, Turbo Hydramatic auto 400 from the Statesman.  Acceleration is astonishing!!  Fuel consumption is similarly astonishing.  Read more on the Fastburn conversion.

Back to original configuration – 253 V8 + M21

Whilst the magnificent 385 Fastburn coupled to a factory “EH” code Turbo Hydramatic 400 provided incredible acceleration, the car had lost its original “feel” compared to my recollections of its earlier life with its 253 and M21 combination.  So after collecting original factory parts for an entire 253 + M21 driveline conversion over the last 15 years, “just in case”, I have made the decision to revert back to its original factory configuration.  A whole lot less power, but they way Holden engineers had optimised it in the first place.

My original 253 engine had been sold in 1979 and although it was confirmed by SA Roads Authority to still be driving around in a registered Bedford vehicle in Adelaide as late as 2008, I have been unable to track down the owner to make him / her a ridiculous offer.  However, after many years of searching I found a 253 block, with an original bore, that, based on some  research was most likely cast in the same batch / day as my original engine.  My original engine number was QR245145 and the replacement block is QR241754 with casting date code J262 (26 September 1972).  The difference in the engine numbers is 3,391.   As engine numbers were allocated sequentially (across all engines, no matter whether L6 of V8), this indicates that my GTS was assembled roughly 3,391 Holden cars after the car that bore the QR241754 engine.  At approximately 600 cars produced per day across all Holden production plants at the time, that equates to about 5 and a half days between the days when the 2 engines were fitted.  As near as I will ever get to my original dated engine.

Update:  11th Sep. 2019.  The installation of the rebuilt 253 and M21 and all accessories was completed.   The motor fired up first time and ran perfectively.  The M21 gearbox shifted cleanly through all gears.  The new drivetrain was then run in on a car club run to Erica.