^ What Dan said ^ especially the part about bigger is not always better.
I’ve always found it best to do some 1/4 mile runs with various carbs or if you have access to a dyno, that works too. This makes it obvious which carb is working best for your setup.
You realize there are a lot of original K codes that did not have a VIN code stamped on engine or trans.
You are speculating unless you have any original source documents from Ford saying K-code engines were not stamped. I'd recommend not perpetuating something that you cannot prove, although I acknowledge it is likely true but I never claim it to be fact. Do you have a mismatched vin you'd like to enter, warwick?
For those of us who have been in this hobby for multiple decades, this topic has been discussed over and over and over. Personally I know 20 years I commented on the original HiPo site where the conclusion was (and has not changed) that it was more common to have a VIN stamp on a San Jose car than Dearborn or Metuchen. There are many examples of documented to day 1 cars without a VIN stamp (I happen to have one of those) and have spoken with some VERY WELL RESPECTED people on this site who have owned K cars with AND without VIN stamps. Furthermore, my beef going back to the 90’s and original HiPo site was always how do you authenticate someone randomly entering a VIN in a database...either the HiPo site or Tony Gregory or any other sites out there?
To prove my point, you can add these VINs to your database (don’t), 6T07K123456 and 6F08K123456 and 6R09K123456 and without someone inspecting any of these ghost cars, you have zero proof that they are authentic.
It is also a known fact that people can and have fraudulently added VINs to fender aprons AND drivetrains so the words “buyer beware” are always appropriate with these and other high dollar muscle cars
Kevin,
Some additional food for thought:
1. Mobil 1 15W-50 is formulated for flat tappet engines. This is all I’ve used for the past 35 years and has and both phosphorus and zinc levels can be found here https://www.mobil.com/lubricants/-/m…C94A7396657AC09
2. If you need to bore the block, depending on the severity of damage you can go to .040 instead of .060.
3. I’m sure you’ll discover the root cause when you do a tear down but with metal debris on only the drivers head and extra loose valves, did you also check for bent push rods?
Valves definitely sound loose, start there. Where does the oil pressure needle sit at idle? Although not the most accurate, anything below midpoint would could concern. You can add a mechanical gauge by putting a T fitting on where the stock pressure gauge is.
It could be a rod bearing but that knock usually becomes more pronounced during engine deceleration. Have you tried to rev the engine and does the noise change when the revs come down?
As a precaution, you may want to drain the oil to see if there is any sign of metal in it.
