Second type not "series 2". They aren't easy to find, very early GTS350 owners want them too. If yours is one of those GTS327's that were built expecting a Chevrolet 327 but retrofitted with a second type Canadian 327 that carby you have might do you as some of those got the late 1967 spec carby like you have.

No. It is a bit convoluted how it all came about but I'll try and summarise.

GMH appears to have only initially intended to build 500 of the GTS Special, which was to be an option package on the GTS but later became its own model and name changed to GTS327. The car was intended for GroupC racing, spearheaded by Norm Beechey. The initial batch of 500 engines would have been planned and ordered and were built at Tonawanda in late March and early April 1968. The engine was a regular production engine for Chevrolet and what went into the local 1968 GMH assembled Pontiac and Chevrolet. It was built at Tonawanda as McKinnon didn't build a 4BBL 327. For the engines in 1966 and 1967 GMH assembled Pontiac and Chevrolet they were bitzas as the low compression 4BBL 327 was not a regular production engine. McKinnon Industries built these using Saginaw cast blocks, with parts from other casting plants. However come the 1968 vehicles and the HK it was a very common engine option RPO L73. The engine in the local CKD cars was full north american spec, including 1968 emissions equipment that became standard across the bard in 1968 in North America. The HK engine got a 1967 spec carby though as we didn't get this emissions equipment until during HQ (ADR27), that is why the HQ 350's after about 9/73 get US numbered carbs again. The HK also got a unique sump and pickup and lost the LHS emissions exhaust manifold and instead got a swept back example better suited to the chassis. Most of the North American 7027213 DZ carbs you find are the prior generation Quadrajet body, that Carter began to make for GM later. Some do turn up, possibly Canadian spec or some other reason that look the same as the HK carby. I have seen 0038 and 0278 codes on them here in Australia. That sort of explains the first type engine and carby.

What happened though was GMH decided to enter the GTS327 in Series Production, specifically for the 500 mile race at Bathurst. This was a very late decision that saw the GTS327 modified significantly as it would have to race stock. GMH almost got tripped up by the ARDC (who ran Bathurst using eligibility different to CAMS). The ARDC wanted 200 identical cars with the same diff ratio, same adjustable or non-adjustable seats etc. GMH couldn't actually claim this. So extra cars had to be hastily added to the production schedule which also meant dealers could sell them. This meant that the original planned engines supposed to last until the end of HK would run out by the end of 1968. This meant the original 500 engines plus the next two batches made in May and July 1968 were not enough. To compound matters further, the 4BBL 327 was finished by the end of July 1968, so no more production 4BBL 327's, there was only two 327's left for 1969 US vehicles and they were both 2BBL. So McKinnon Industries had to build a special 327 for GMH - they are full McKinnon castings other than the intake (as McKinnon didn't cast a 4BBL manifold and one exhaust manifold). The kicker though was it was a 1969 dressed engine hence the alternator and water pump were different. It appears GMH went on producing GTS327's to schedule expecting the new engines to fit - remember they didn't get any 1969 spec 350 engines until mid 1969. So when they tried to fit them in December 1968 it must have been a bit of an "Oh Bugger" moment, and some parts were modified to fit, like the shroud for example.

Also note that the carbs were not on the engines when they arrived, they came separately. As GM no longer used 1967 pre-emissions carbs anymore, they had to create a GMH specific set of numbers for the local Aussie carbs (it stayed this way until 9/73). The carbs they sent for the later GTS327's that you are looking for are the same tune as the 7027213 DZ carb, just a different number, so they are interchangeable. As the carbs came over in bulk, naturally there will have been surplus or shortage, and it does appear that a few of those mid to late December 1968 GTS327's with the Canadian bitza engine actually got the earlier carb. The same applies to very early GTS350 manual, they got the 327 carb as it was identical bar the way they were numbered.

Yes, the McKinnon 327 in HK were 386 castings, cast at McKinnon Industries. Interestingly that casting was replaced at Saginaw by 618 and at Tonawanda by 388 around the end of 1968. All of the three casting plants began using 010 in the second half of 1969. I haven't yet found what or if McKinnon cast any 4" bore blocks between the end of 1968 and when they started using 010.

The engines were all stamped the same way, other than using T, V or K with MM/DD after it.

All GTS350 manuals had the same spec carby, it is just how it was stamped and whether they had the broadcast sheet code and/or the date code on them. The very first GTS350 completed was Pagewood 1-H5 and it had the same stamping format as the second type 327 carby. The first HT 81837 which was 1-A had a 327 in it so it also had the second type 327 carby. I don't know how many got this carb until the 29283 stamping began. 4-H5 was missing its carby. 5-H5 was an auto and also missing it's carby.

No, I have never had any info on them. Only 1 and 4. 1-H5 is a well known car, it was the car at the Bathurst Holden dealer that had it's sump cut open to prove to Ford and the ARDC that it had 4 boot mains. It still had its original carby. 4-H5 I know the restorer, I gave a carby to him for it which was one of the first 29283 stamped carbs but got it back when he sold the car without it. 5-H5 I saw the tags off retrofitted to a South African SS body in Sydney Region a few years back, I can't recall how we knew it was an auto, the engine might still have been with it.