There was only two specification of engine for each size. For the 307 and HQ 350 the difference was the bellhousing and clutch versus a flex plate. For the HT-HG 350 the difference was greater but only because they were different engine specs (L48 300hp base vs LM1 255hp base). Of course the 327 only came in the one spec as they were all manual, and the automatic versions (also an L73 base) came as part of a mechanical pack for each CKD vehicle, not just a container full of engines in crates like the Holden engines did. The individual specs did change over time as we know, like the baffled sump introduced to 327 mid HK or the change from Chevrolet engine plant supply to GM engine plant supply.

All of these engines in a Holden were the performance engine at some stage. 307 initially, then 327, later 350. Although the HT/G 350 were actually different engines GMH basically treated them the same but with a different spec depending upon your transmission choice.

Although it is unlikely you will see it today, it used to be commonly seen (at least locally to me) on HJ to HZ vans. Most local here were Pagewood Assembly with others from Acacia Ridge. The same phenomenon existed with all Eluzabeth assembled cars plus Dandenong vans and cab-chassis. I used to see it in the 80’s and 90’s and dismissed it as respray but in reality it was for example an Elizabeth body assembled at Pagewood, where the front panels were an obvious different shade to the firewall backwards. It was more obvious on silvers and dark colours. With Elizabeth (and Mosman park) assembly they painted their front panels later in the assembly process where the other plants painted the front panels in the same booth as the body and they were re-united in the assembly plant, except of course for the vehicles where the bodies were painted at Elizabeth and assembled at Pagewood, Dandenong (and Mosman Park). What I’m getting at is with the higher level of paint finish on the exterior we could easily see that even at Elizabeth where the body plant and assembly plant probably even shared paint source you could clearly see the variation simply as it wasn’t all painted at once. So if that was difficult, imagine the variations between engine colours where no-one really gave a toss about it, where we are talking varying paint sources across Ontario, Buffalo region, Sydney, Melbourne etc, being painted in different areas of different plants at different temperatures using different thinners. There was always going to be variations.
All I’d do is paint the engine in a colour that looks close to remnants off your original engine and if it’s displayed simply state on the display board that the engine is painted to closely match the original remnant paint found between the bellhousing and the gearbox. State that the GMH specification was X2 engine red and it has been replicated to the best of your ability. Unless a concours judge has to split hairs I doubt it’d ever have to be questioned. I’m sure every car would have other problems of far greater significance than a slight engine colour variation. And to be fair I bet all the concours cars are over-restored anyway with no overspray, engines far neater than any one ever was etc. have you seen some of the untouched shockers with firewall paint like someone sneezed it on there or where the ID tag mask has moved and the tag is half covered in black paint or even red lead primer? They were mass produced, close enough was good enough.

To determine the exact color you need to call a woman :) For men, everything that is red is red, yellow is yellow. Well, that's my way :)

Hi All,
While on the subject of red Paint. I painted my Monaro according to the colour code on the ID Plate (Spanish Red). But the guy at the Paint Shop gave me Firethorn Red which is exactly the same colour code as my Monaro. That was back in 1990.
If I want to respray it now, how do I find exactly the right Red ?

Hi Terry,

So it is the same Colour, ok that's great I didn't stuff up.
I've been wondering about that for years.

Thanks Terry.