Craigslist Find

[6667fan]

That is very interesting about the ground off H. The casting does look rough after the C8AE. Thanks for sharing that. I have not disassembled heads yet.

[427John]

Yep, all production CJs are C scratches, but not all C scratches are CJs...until you go to sell them

Did all C scratch blocks have the extra webbing?I've seen A scratch blocks without it,did some A scratch blocks have the extra webbing?

Yes, extra webbing started before the C scratch.

So early A scratch 428 blocks had standard webbing and then later A scratch and all C scratch blocks had the extra webbing?I didn't realize all later 428 blocks had the extra webbing.Did the 66 solid lifter PI block have standard webbing?Was there a PI scratch block?

[thatdarncat]

Yep, all production CJs are C scratches, but not all C scratches are CJs...until you go to sell them

Did all C scratch blocks have the extra webbing?I've seen A scratch blocks without it,did some A scratch blocks have the extra webbing?

Yes, extra webbing started before the C scratch.

So early A scratch 428 blocks had standard webbing and then later A scratch and all C scratch blocks had the extra webbing?I didn't realize all later 428 blocks had the extra webbing.Did the 66 solid lifter PI block have standard webbing?Was there a PI scratch block?

The 428 Cobra Jet website has the current known date spread of the “A” & “C” scratch blocks and the start of the three finger webbing, check out the link. As far as all the later 428 blocks, remember that Ford cast 428 blocks at the Dearborn Iron Foundry well into 1974, I don’t know if anyone has analyzed all the later versions to see if the three finger main webbing kept going to the end of production, but through the 1970 model year, yes. Most 428’s have some scratch mark in the back, it was Fords method of differentiation, most car blocks are “A” or “C” from ‘66-‘70 depending on date, and that would include the 428 PI, but there are some lesser seen ones.

Link: https://www.428cobrajet.org/id-block

[Rory428]

Personally, I have owned 14 428s, and worked on several others. Now, this is just what I have seen with my own eyes, but all my A scratch blocks were from Thunderbirds/Galaxie and full sized Mercurys, and none of my A blocks had the triple webbing. All my C scratch blocks were from CJs, and had the triple webbing. So I have never owned a triple webbed A block, or a C scratched block from a non CJ car. Not saying they didn`t make them, I just have yet to own one. Similar to 428 cranks, I have had 1U, 1UA& 1UB cranks, and although it is often said that some Cobra Jets had 1U cranks, every 1U that I had came from a non CJ car model, and every CJ that I had was equipped with a 1UB crank. Even my 1973 dated 428 CJ service short block currently in my 59, has a 1UB crank. Now, that said, upon close inspection, I have never been able to notice any visible difference between a 1U and 1UB crank, unlike the 1UA SCJ cranks, which are missing the small "boomerang" counterweight near the center. Again, just my own personal experiences.

[Gregwill16]

I misspoke above about the C scratch starting in March of 67. I mixed up the C scratch and the triple webbing.
I personally owned a June of 67 (7F) C scratch which is supposedly when it started. I also owned an April of 67 (7D) A scratch with triple webbing. The CJ site claims the triple webbing started in November of 66. I had a mid November 66 428 block that did not have triple webbing, but I have not owned anything between that block and the April 67 block, to give an opinion.

[wsu0702]

Personally, I have owned 14 428s, and worked on several others. Now, this is just what I have seen with my own eyes, but all my A scratch blocks were from Thunderbirds/Galaxie and full sized Mercurys, and none of my A blocks had the triple webbing. All my C scratch blocks were from CJs, and had the triple webbing. So I have never owned a triple webbed A block, or a C scratched block from a non CJ car. Not saying they didn`t make them, I just have yet to own one. Similar to 428 cranks, I have had 1U, 1UA& 1UB cranks, and although it is often said that some Cobra Jets had 1U cranks, every 1U that I had came from a non CJ car model, and every CJ that I had was equipped with a 1UB crank. Even my 1973 dated 428 CJ service short block currently in my 59, has a 1UB crank. Now, that said, upon close inspection, I have never been able to notice any visible difference between a 1U and 1UB crank, unlike the 1UA SCJ cranks, which are missing the small "boomerang" counterweight near the center. Again, just my own personal experiences.

The 428 crankshaft changed from 1U to 1UB in mid November of 1968.  The counterweights are slightly larger on the 1UB to match the new heavier pistons that were introduced at the same time.  More meat was added around the 428 piston pin bosses to resolve a cracking problem that was causing a lot of warranty returns.  This change was applied to all 428 engines including the PI and industrial engines.  So IUB is not a Cobra Jet only crankshaft.

[gt350hr]

  " A" scratch blocks were also used in well over a thousand '67 GT500 Shelbys. There are several accounts of three rib , "A" blocks from reliable sources including pictures of them. Certainly NOT common by any means as were the C scratch blocks where there have also been reports of extremely rare NON three rib blocks with the C scratch. Like Rory , "I" have never owned a three rib "A" scratch block but know they exist.
  Randy

[thatdarncat]

I have a three rib “A” scratch 428 block. 7B24 casting date. They’re real 

[wsu0702]

  " A" scratch blocks were also used in well over a thousand '67 GT500 Shelbys. There are several accounts of three rib , "A" blocks from reliable sources including pictures of them. Certainly NOT common by any means as were the C scratch blocks where there have also been reports of extremely rare NON three rib blocks with the C scratch. Like Rory , "I" have never owned a three rib "A" scratch block but know they exist.
  Randy

In my 35 years of searching for 428 (and FT) block I have never seen a C scratch block that did not have the extra ribs to the main saddle.  Even the late service blocks that did not get a scratch mark had the extra ribs to the saddles.  I would love to see evidence of a C scratch 428 block that does not have the extra rib to the main saddle.