Prices are up…most places, but I just got Mobil 1 15-50 (has correct zddp) at Walmart for USD $27 for 5 gal jug. Other oils , antifreeze, and car stuff much cheaper than anyother autoparts chain store, where good oil is 8-11$ per qt, 37 to 42 per 5 qt. The Walmart in little ol Spokane WA now has a Police car and a security car parked in front while store is open, and a staffed metal detector gateway at the entrance, a staff at the exit only doors. also…–in usa–autozone will take used old oil–up to 20 qts.
An aside: I still want a special custom wrench,–thin, with the right bend, to fit and turn the engine via the big odd size nut on the front of the engine crank/lower pulley. For mine at least…the nut sits in a depression in the pulley center–so a wrench end barely fits on…the arm of the wrench against the pulley center. While a socket will fit on the nut, there is no clearance. room for the wratchet handle to fit.
Nick
Home Depot, a bit of polishing with a gas axe, and yer set!
https://www.homedepot.com/p/TEKTON-1-15-16-in-Combination-Wrench-WCB23049/302361469
Woops… 1-5/16", but you get the idea.
Ouch! I think I would go to Ace Hardware and buy a 1-5/16" socket for $10 and spend another $7 for a piece of flat steel bar and weld them together.
That’d work, too! Just make sure it’s a 12 point socket… 
That’s one expensive wrench. Try Harbor Freight
As I recall I used a 6" extension with a socket and turned it from the front of the car. It might have been a 12" extension. At my age distance is relative.
Haha, that’s cheatin’ Pat. 
The problem with the XK120 is there’s not a lot of room.
My regular 1-5/16" socket won’t fit in there.
What’s the opposite of a deep well socket? Is there a shallow well?
Looks like your best bet is to get a box wrench and have somebody with an oxy/acetylene torch bend it into a chicane shape.
$12.09 on Amazon
https://www.amazon.com/Performance-Tool-W376B-Jumbo-Wrench
More ways to skin the proverbial cat. Lots of engines use a 3/4-16 damper bolt. ARP makes a 12 point variant for several of them. The 12 point bolts take a 13/16" 12 point socket or box end wrench. Very compact. You can find them cataloged for most mid 50’s-70’s Chrysler V8s, Buick V6 and Oldsmobile V6 and V8. Also, some Boeing mil-spec surplus landing gear.
I have several ancient Whitworth ring spanners with goosenecks and the ones that have 3/4" W on one end reach up perfectly from below and allow you to get right on the nut on all Jags I have come across.
I will take a picture of one
Or, eliminate the socket altogether. The Chrysler, Buick and Olds version of this bolt would swap. Note that this only engages every 90 degrees,not nearly as convenient with the engine installed.
I usually like your fastener upgrades, but that big crank bolt has never given me any trouble, and I cant really see how it ever would, maybe if you want to save every gram on a race engine
I recently acquired a 12 point 33mm 1/2" drive socket.
I would be surprised if I cant get that onto it
My 1-5/16 and 3/4W sockets are 3/4" drive and that does make it hard to get them in situ
And mine, as well. The 13/16 12 point head just makes it so much easier to deal with in situ.
that does make sense,
when I take my pic tomorrow, I will see if my 33mm x 1/2" will work like my Whitworth spanner, ie, I do not have to lift the car at all, can just reach up from the ground
I have the 1-5/16" in a 3/4" drive, but I have NO clue why: I do have a copy in 1/2 drive.
I can see how a 3/4 drive would be hard to get in there, being so chunky.
All my Imperial 1/2" socket sets have 1-1/4" as the largest size, although no doubt you can get a 1-5/16" in 1/2"
Metric sockets are standard 1/2" drive up to 36mm
The 33mm one was on sale for $12, it will have one job in life,
its a very tight fit on the bolt head
The 3/4 drive gear gets in the way, as its so much bulkier…but you know all that 
good thoughts…I think I want to see IF–I can get a 1 5/16 socket cut all the way thru so it is thin in depth, …just the same depth as the big nut…then weld a flat handle…In place–there just isn’t much room. I have need to turn my engine–for timing etc only very occasionally…but I find in helping others set up timing–it comes up more often…and is a PIA.
Nick
Look on Amazon: Proferred T46024 Combination Wrench 1 5/16 $6.19 Take a torch and bend it into an offset
As promised, here is a comparison of some crank bolt rotating tools
The winner is 3/4W crank spanner as pictured.
The max space in next pic between fan shroud and damper pulley is 1"
I have 3 of these spanners as pictured below, only 2 would easily fit on the bolt with me just lying on the ground, vehicle not lifted at all
The thicker built one has the same offset, but is sturdier, and I couldnt wiggle it on
The ideal neck crank distance is ~ 1" and slim profile. The middle one is my main man
None of these configurations can get on from below without removing the fan shroud
1-5/16 x 3/4" 33mm x 1/2" and I found I have a 3/4W x 1/2" socket, which is shortest of all, so I wasted my $12 on the 33mm 12 point
There is a number of used 3/4" W spanners on eBay, and that may possibly be the best way to go
@Mike_S suggestion of different size crankbolt makes more sense to me after that exercise, especially if you are a long term owner who likes to tinker
Radiator or engine out would be the time to do it
I have a specialised Industrial fastener shop 20mins drive away.
I write down all the stuff I need and visit them periodically,
might see what they have for this
