Pulled the trigger on a Mirror 105 Engine - Really glad I did!

[Gaugster]

Hey all - This engine was dropped off today. My goal was to find a suitable block for a stroker motor that will make good used and Jay's new head technology. Hit pay dirt as it came with a 428 crank. (Updated 4/1 - crank is actually a 3U so I screwed the pooch on this) Had to measure it twice as I was in disbelieve. It would appear to be a 0.030" over 390 block with a 428 crank and the GT iron "S" intake. It will be another week or two before I can start disassembly. What's the best technique to pull out the core plugs to perform the drill bit test?

[Gaugster]

A few more pics.

[427John]

Gaugster,many years ago I was inspecting a 69 Cylcone GT R code for possible purchase.I noticed that it had the mirror image 105 block and asked about it,the owner who claimed to be the original owner and had receipts dating back to 1969 though I never saw the original registration with his name,claimed that the engine had been replaced under warranty in 1974 and that D3TE and D4TE 391 truck blocks were being used as service replacements by then according to what he dealership service manager had told him.I don't know how much truth there was in this fairy tale but am relating what he told me,I do know some 391 truck blocks were cast with thicker walls by using the 428 jacket cores,I have personally seen a couple that had the the 428 cast in the bottom of the water jacket,so its something to keep in mind when you tear down and inspect.If by chance you do find the 428 cast in the bottom of the water jackets and get the block sonic checked please post the results.The way I remove core plugs is I have a tire iron that has the lug wrench end cut off and I use that as a punch at the edge of the plug to drive one side in as it starts turning grab the edge with channel locks and pull it out.

[67xr7cat]

Gaugster,many years ago I was inspecting a 69 Cylcone GT R code for possible purchase.I noticed that it had the mirror image 105 block and asked about it,the owner who claimed to be the original owner and had receipts dating back to 1969 though I never saw the original registration with his name,claimed that the engine had been replaced under warranty in 1974 and that D3TE and D4TE 391 truck blocks were being used as service replacements by then according to what he dealership service manager had told him.I don't know how much truth there was in this fairy tale but am relating what he told me,I do know some 391 truck blocks were cast with thicker walls by using the 428 jacket cores,I have personally seen a couple that had the the 428 cast in the bottom of the water jacket,so its something to keep in mind when you tear down and inspect.If by chance you do find the 428 cast in the bottom of the water jackets and get the block sonic checked please post the results.The way I remove core plugs is I have a tire iron that has the lug wrench end cut off and I use that as a punch at the edge of the plug to drive one side in as it starts turning grab the edge with channel locks and pull it out.

Never seen a MCC 105 block with 428 water jacket cores.  Considering that MCC could not use the DIF cores and had to make all new ones I would tend to believe those who were there and have said all they made was 390 type blocks.  Many of them came with the large distributor hole and the oil return drilled.  If going into a light duty truck they would use a bushing in the distributor hole and plug the oil return.

I know some say you can bore the MCC blocks out to 428 size.  If you get a block with no core shift may be safe, but I would not believe for a minute that it was cast with 428 cores.  There are a few 391 blocks that had the 428 water jacket cores, but all I've seen or heard of came for DIF and seems a 1968 casting date is common.  Also have heard of some passenger car 390's that turned out to be a 428 block with a 4.05" bore.  They all have had the C scratch.  Considering Ford had a strike in 1968 that screwed up production may have something to do with it, but who knows...

One nice thing about the 105 MCC blocks is they all have the crows foot main webbing.  Bad thing is they tend to crack at the oil passage to oil the heads. Something to check for.  If cracked can be sleeved with a piece of tubing.

Removing core plugs, I just knock them in with a hammer and chisel, grab the lip with vise grips and pry them out. 

[Gaugster]

I'll be heading out to the garage tonight to pop open the core plugs. Very curious about what I got. Will measure the water jackets tonight and hopefully confirm the extra webbing later. I find it interest that the block has D3TE - 1973 Truck Engine but yet 4E1 - 1974 May, 1? I suppose the E could be an L but I though the number was the year? Is it showing both 1973 and 1974 or am I confused? Perhaps Engineering numbers have a different purpose than date codes?

[thatdarncat]

Like 67xr7cat said - All the 361/391 FT blocks with 428 cylinder cores I’ve seen so far have come from the Dearborn Iron Foundry (DIF). So far the ones I’ve seen were all ‘68 & later dates, through the end of DIF production. You won’t find a “428” at the bottom of the water jacket of a MCC 105 block. When MCC started they promoted a more precise casting process, you might find less casting shift, but I’d still advise sonic testing, I’ve seen tests of a few that looked like any other FE.

You answered your own question - engineering numbers aren’t date codes, that’s why there’s also still a date code on it. Engineering numbers don’t necessarily change every model year, some engineering numbers remain unchanged multiple model years.

[Gaugster]

Okay. Drill bit test confirmed the obvious. 7/32" (14/64") is the largest bit that will fit. 15/64" will not. So there's no missing link here.

The comments about 1968 DIF blocks is interesting as that is what the Cougar has in it now. No C scratch or anything remarkable on the rear bulkhead. I assumed the current block is nothing special in FE land. Guess I will find out one day.

[brettco]

Gaugster,many years ago I was inspecting a 69 Cylcone GT R code for possible purchase.I noticed that it had the mirror image 105 block and asked about it,the owner who claimed to be the original owner and had receipts dating back to 1969 though I never saw the original registration with his name,claimed that the engine had been replaced under warranty in 1974 and that D3TE and D4TE 391 truck blocks were being used as service replacements by then according to what he dealership service manager had told him.I don't know how much truth there was in this fairy tale but am relating what he told me,I do know some 391 truck blocks were cast with thicker walls by using the 428 jacket cores,I have personally seen a couple that had the the 428 cast in the bottom of the water jacket,so its something to keep in mind when you tear down and inspect.If by chance you do find the 428 cast in the bottom of the water jackets and get the block sonic checked please post the results.The way I remove core plugs is I have a tire iron that has the lug wrench end cut off and I use that as a punch at the edge of the plug to drive one side in as it starts turning grab the edge with channel locks and pull it out.

Never seen a MCC 105 block with 428 water jacket cores.  Considering that MCC could not use the DIF cores and had to make all new ones I would tend to believe those who were there and have said all they made was 390 type blocks.  Many of them came with the large distributor hole and the oil return drilled.  If going into a light duty truck they would use a bushing in the distributor hole and plug the oil return.

I know some say you can bore the MCC blocks out to 428 size.  If you get a block with no core shift may be safe, but I would not believe for a minute that it was cast with 428 cores.  There are a few 391 blocks that had the 428 water jacket cores, but all I've seen or heard of came for DIF and seems a 1968 casting date is common.  Also have heard of some passenger car 390's that turned out to be a 428 block with a 4.05" bore.  They all have had the C scratch.  Considering Ford had a strike in 1968 that screwed up production may have something to do with it, but who knows...

One nice thing about the 105 MCC blocks is they all have the crows foot main webbing.  Bad thing is they tend to crack at the oil passage to oil the heads. Something to check for.  If cracked can be sleeved with a piece of tubing.

Removing core plugs, I just knock them in with a hammer and chisel, grab the lip with vise grips and pry them out.

I came up with a S scratch nov 66 4 lug bottom end large dist.hole block that is a 4.08 current bore block. 13/64 drill biting appears to be a 428 block bored bored 390 use or the 391 also had scratches in the back?

[Gaugster]

Well I was able to get the engine on my stand once the plate arrived in the mail. Turns out I blew it on my stroke measurement. Got had by Pythagoras's theorem it seems.  I've got a 3U 390 crank instead of a 1U 428. Still a good item though if it cleans up nice. What I was really after was a webbed block and thankfully that's what it has. I can observe that 6 out of the 8 cylinders still have honing marks from the last rebuild. Almost no carbon ridge at the top of what turns out to be a 4.08" bore.

[Gaugster]

Curious about the differences in the two water passage designs. I have always associated the larger triangle passage with 428 blocks and the smaller with 390/360 blocks. Never used it as a telltale but rather a "good sign" to inquire further. The larger one is from my 1974 block whereas the smaller is from the 60's.

 

[thatdarncat]

Curious about the differences in the two water passage designs. I have always associated the larger triangle passage with 428 blocks and the smaller with 390/360 blocks. Never used it as a telltale but rather a "good sign" to inquire further. The larger one is from my 1974 block whereas the smaller is from the 60's.

The larger more triangular shaped deck coolant passages are a 428 cylinder core tell tale, but ONLY on the Dearborn Iron Foundry (DIF) cast FE/FT blocks. Ford employee Dennis K. shared that it’s actually called out on the blueprints for the DIF blocks, as is the round coolant passage shape of most DIF cast 427 blocks. Ford was obviously using that as a method to differentiate between the various types of FE/FT blocks they were casting at DIF. But all Michigan Casting Center (MCC) blocks have that coolant passage shape, it’s meaningless for MCC blocks. All MCC blocks have the three finger main webbing too, so no surprise what you found there. For whatever reason Ford just decided to use those features in the molds of the new MCC blocks.

[427John]

So how long did DIF continue to make FE blocks?Were mirror image 105 blocks all MCC castings,that was an indicator?That wasn't the only time I had heard the D3TE/D4TE as 428 service replacement fairy tale,I had also seen it in print somewhere possibly in the Steve Christ book,it had plenty of such misinformation.That may have been the source of the bullshit story the owner of the Cyclone fed me.One other question about the MCC blocks,did they all have the threaded hole for the support bracket bolt for 4x4 and FT oil pump pickup tube?His engine appears to have a front sump pan and wouldn't need it,was that another standardization thing done on them like the crows foot webbing?

[thatdarncat]

So how long did DIF continue to make FE blocks?Were mirror image 105 blocks all MCC castings,that was an indicator?That wasn't the only time I had heard the D3TE/D4TE as 428 service replacement fairy tale,I had also seen it in print somewhere possibly in the Steve Christ book,it had plenty of such misinformation.That may have been the source of the bullshit story the owner of the Cyclone fed me.One other question about the MCC blocks,did they all have the threaded hole for the support bracket bolt for 4x4 and FT oil pump pickup tube?His engine appears to have a front sump pan and wouldn't need it,was that another standardization thing done on them like the crows foot webbing?

DIF cast 428 blocks well into 1974 I believe, one of our members had a pretty late 428 service block, maybe he has the date.

The mirror 105 blocks are all MCC blocks, but not all MCC blocks have the mirror 105, just like not all DIF blocks have the “352” on the front.

Not sure about the bracket bolt hole, maybe a few people can look, I think all the MCC blocks I have at the moment were FT’s, so they all have the hole.

[427John]

I've seen multiple instances where the 105 block pickup engines that had a front sump pan had that hole but didn't know the history of the engine,it could have been swapped out of a 4x4,and don't remember if I've seen one without it but that means nothing.

[Gaugster]

So here's a look at the rod bearings. Anyone seen wear like this? Normal? I think I am looking at fretting on the mating surfaces of the bearings to the rod/caps? When taking out the pistons several of the bearings separated from the rods and just stuck on to the crank journals. Even had one rod bolt that backed out rather easily. My first time looking at this stuff but I am guessing these weren't setup right and rather loose. Probably had lower oil pressure too. Or I'm just overthinking it.