It’s no doubt been discussed a number of times on here. Can yous bring me up to date though. What are the main issues, the things to be weary of and keep an eye out for.
What are the main concerns when replacing a 186 / powerglide with a 307 / power glide
Are there any concerns mating the 186 powerglide auto up to the 307 Chev and linkages, speedo etc. What are the options for the gear changer.
Thanks in advance.
aKabud.

Presuming you're talking about HK or ht, still need to know whether you presently have column shift or floor shift. I might have misinterpreted your post, but you are going yo need a V8 powerglide to go with the 307, I don't believe that you can just bolt up the 186 one

All HK and HT 307 were 1968 model engines, and all from the Canadian engine plant. 1968 model engines were made from August 1967 to July 1968. The 307’s used in HT were engines originally intended for HK but not used for a number of reasons.

307 was optional in all HK models except where it was standard (Brougham) or GTS327 where 327 was standard.

307 was sort of optional at the start of HT except on Brougham where 308 was standard and GTS350 where 350 was standard. 307 was only available on V8 HT models which in HT were a different model to 6cyl versions. The V8 HT models other than Brougham and GTS350 were standard with 253 manual (3spd) or M21 4spd in the case of V8 GTS with the M21 4spd optional on other V8 models. There was no auto option, if you wanted a V8 auto you got 307 and Powerglide. This remained until 307 were all used and from then onwards V8 models were available as 253 manual (3 or 4spd), 253 Powerglide, 308 4spd or 308 Powerglide. There were some late HT with Trimatic.

I’ll list your parts you need in another post. However I need to know if your HK is console shift or column shift.

Edited by user Saturday, 18 September 2021 8:14:59 PM(UTC)  | Reason: Not specified

It'd be cheaper to buy one already done. If you were to convert a HK 6cyl to V8 today you'd not do it as per original, would cost you way too much as some of the parts you'd need are really hard to find and costly. Like a nodular iron Borg Warner made banjo V8 diff centre, a HK-HG SBC style sump and pickup, column shift crossover mechanism etc. Even a V8 Powerglide will cost you $1000 for a rebuilder today. Your best bet would be to buy an engine that didn't come from a Holden or Statesman, like a GenII small block which bolts in the same as a SBC. Use a TH350, and run a B&M shifter. Or if you want column shift fit a V8 Trimatic with RH shift and get a Chevrolet pattern bellhousing for it, and fit a HG column and linkage. Run a 9" or a Borg Warner. In the end will be a lot cheaper. With the Trimatic you wouldn't even have to holesaw a speedo cable in the firewall.

Note there was no floor shift auto in HK-HG. Only column shift or console shift.

GMH Engineering docs often call it M11 console shift for automatic, although sometimes they mix it up and state M11 Console Floorshift. Floor shift is normally reserved for manual only, and it is very rare outside of commercials. Dealer Order forms get confusing too, they often say stuff like Floor Shift Console or incl. M11 Floor Shift or M11 Console Shift. I find it far less confusing to call them:

Column Shift
Floor Shift.
Console Shift.

That way there is zero confusion.

I do not put any faith in what marketing did as they screwed lots of things up. Most sales brochures do not even show images of the vehicles they are marketing.

How would a Salibury Diff match up with the HK307 SBC & Powerglide, a friend has just told me he may be able to help me with one.Is there any particular one or are they all the same ? Thanks for all the help here.
aKabud

Not quote right. 6cyl console shift Powerglide and V8 Powerglide are basically interchangeable shifter wise. However column shift aren't. The crossover mechanism is very different. 6cyl goes across the front, same as HD-HR. V8 is at the back of the box for both 307 and 253/308. The V8 boxes also have the different rear housing with different rear mount, which is also why the speedo cables are different as they are in the extension housing. They are not interchangeable. The column is teh same from memory.

As Sandaro says a HK-HG Salisbury will fit but the body is different so it won't bolt in using factory bits, example the body mount for the rubber brake hose is in a different location. There is a hump in the body and the fuel tank to clear a Salisbury diff but you don't need it for a 10-bolt Salisbury, only for a 12-bolt which are so rare anyway as an original item not worth talking about.

Yeah ! I think he was talking about a 10 bolt probably out of a Monaro, I’ll better check that when I catch up with him again. Is there no problems with body clearances with 307, powerglide and Salisbury. So with those 3, the 6 cylinder linkages will do the job but your’re saying the 6 cylinder transmission support x member is different, is it a different one altogether or can the 6 cylinder one be modified to suit. I am familiar with the Chev Saginaw set up but, seems there is a bit more involved with Chev Powerglide. Thanks for all the help.
aKabud

Forgot to add.

If you want to run a SBC you don’t need to focus on a 307. Any SBC or GenII GM engine will fit as long as it has side mounts, so 1959 onwards. They all fit the same except the GenII engines use a different flex plate as they have a smaller flange due to the one piece rear main. Plus 400 have a different balancer.

There are a lot of cheap SBC style engines out there still, some near free. Nothing wrong with a 283, once rebuilt most of them will be going 60 over anyway which is 292ci - these usually will go 125 thou over which gives you 302ci. You can also put a small journal 327 crank in 1963 onwards 283 blocks to turn them into a 307, at 60 over they are 317ci or thereabouts. With a good set of heads a 283 or stroked 283 goes well.

With a SBC design engine a TH350 is a better option than a V8 Powerglide in many ways. Uses the same speedo cable and rear mount as a Powerglide but will be messier to setup a shifter as column shift will be a custom arrangement. If you can find a HZ TH350 column shift setup you should be able to operate it with a HG Trimatic column though. The kickdown on a TH350 is by a cable off the carby, and is simple. All said I'd still look into a Trimatic as you can buy a SBC pattern bellhousing for them. The cost of the bellhousing is easily offset by the Trimatic cost and using off the shelf bits (speedo cable for HK M15) or bits you have (like the 6cyl Powerglide crossmember). You just have to find a HG column shift Trimatic linkage/bracket which should be pretty common, and fabricate up a small bracket for the kickdown switch. If you fit a SBC using HK-HG mounts and adapters a Trimatic will push back 3/4" compared to how it would with a 253/308 but this should be able to be accounted for in the crossmember (friend did this). The speedo cable will be OK, but you might have to make a small adjustment in the column turning linkage to move it back by 3/4". The tailshaft will have to be 3/4" shorter too but with a new diff you'd probably have to make one anyway.

Edited by user Wednesday, 29 September 2021 10:06:00 AM(UTC)  | Reason: Not specified

327 was a standard engine in HK too. 307 in Brougham and 327 in GTS327. There is no dramas fitting anything smaller either and normally no dramas fitting a 350 either. You won't have issues with a 308 either as it was standard in HT-HG (standard in Brougham).