1964 390 block with extra main webbing and cross bolt bosses

[Wortttie]

Hello all

I have a block as described in my subject line.  I have yet to tear it down but will soon.  Though I will sonic test the bores I was wondering if this block had thicker cylinder walls than the normal 390 block.  My thought is that these blocks were being cast for a 427 bore but did not have enough wall thickness to pass inspection.  I am probably wrong but I would like to know what you experts have to say.  Thank you for your attention to this inquiry.

[frnkeore]

There is about a 99.9% chance that it doesn't have 427 cylinder cores but, it could have a little thicker cores in it.

Are there any markings on the rear of the block? A picture of that area would help, a lot. Of course a sonic test will tell you what you have to work with. Also, you can pull the expansion plugs and measure between the cylinder walls with drill bits or, I use Allen wrenches and get a good idea of the thickness of the walls by how much space there is between them.

[Heo]

i have a police interceptor block like that. No thicker cyl walls than a ordinary 390 block

[pbf777]

     The additional webbing and the cross-bolt bosses were also seemingly commonly found in the '64 Mercury 410 blocks.   

     Scott.

[Heo]

I  dont know if thats a -64 thing but i have seen several 64 blocks that way

[MeanGene]

     The additional webbing and the cross-bolt bosses were also seemingly commonly found in the '64 Mercury 410 blocks.   

     Scott.

That would be very rare as the 410 Merc FE was 66-67 only

[Dr Mabuse]

Hello all

... Though I will sonic test the bores I was wondering if this block had thicker cylinder walls than the normal 390 block.  My thought is that these blocks were being cast for a 427 bore but did not have enough wall thickness to pass inspection.  I am probably wrong but I would like to know what you experts have to say.

I am an expert reader, and long ago learned that FE's being "thin wall" castings, means that core shift is a major consideration when sonic checking cylinder walls.

Also, FE's are subject to cylinder wall flex and the concomitant reduced horsepower effect. Never ever never bore an FE any more than necessary -- a stroker crankshaft is the best means of increased displacement.

[pbf777]

That would be very rare as the 410 Merc FE was 66-67 only

      Yes, my mistake for not being clear; what I perhaps should have said was:  that I've seen and had several of the 410's that utilize a block that has the casting box on the side and up high (not as typical for FE's) that says "C4AE".  And then of course there's the "C5AE' blocks that also seem to commonly have the additional webbing and bosses, but I haven't witnessed those as being so commonly utilized as for the Mercury 410's.   

     Scott.

[Heo]

Ihave one of those C5AE blocks on a complete engine i dont know
how it looks inside

[MeanGene]

That would be very rare as the 410 Merc FE was 66-67 only

      Yes, my mistake for not being clear; what I perhaps should have said was:  that I've seen and had several of the 410's that utilize a block that has the casting box on the side and up high (not as typical for FE's) that says "C4AE".  And then of course there's the "C5AE' blocks that also seem to commonly have the additional webbing and bosses, but I haven't witnessed those as being so commonly utilized as for the Mercury 410's.   

     Scott.

Nice try but no. Factory-built 410 Mercs were 66-67 only, probably C6ME or C7ME blocks. But one can build a "410" from any 390-360 block (or even a 352). The 3.98 stroke crank did not come out until '66, in both the 410 and 428. Maybe you just saw one that someone built on an early 390 block. I actually have one of those '64 blocks that I am saving to make a 410, as the bores are cherry, and I have std, .020 and .030 pistons. I have another C4 shortblock that I'm hoping is the same

[MeanGene]

Ihave one of those C5AE blocks on a complete engine i dont know
how it looks inside

The C5AE blocks were either 390 or 427 center oilers, with the reason for the new casting number being the new 4-bolt mount flanges

[Heo]

Ihave one of those C5AE blocks on a complete engine i dont know
how it looks inside

The C5AE blocks were either 390 or 427 center oilers, with the reason for the new casting number being the new 4-bolt mount flanges

It was in a -66 galaxie i scraped. It was almost to fast to be a 2V 390 in a fullsize but i dont know what it is
original engine in that car was a 4V 390 according to the engine code. I dont know if just the intake is swaped
or the complete engine. Not crossbolted though so most probably no 427

[pbf777]

Nice try but no...................

      If it's just that I'm failing to communicate properly I apologize.      But if it's because your failing to understand, and/or perhaps your just not familiar with the subject which I have attempted to bring to light (perhaps not so clearly initially, yep, my bad) and with a closed minded perspective you have chosen to engage another, well then, I surrender, you win!   

      But realize that just because the casting number might be "C4" (and it was my mistake to utilize the simplistic reference of "'64" vs. "C4"), this doesn't necessarily mean that is actually the year in which it was cast.   

      Some battles just aren't worth the effort!   

      Scott.

       

[MeanGene]

If you do a little research, you will find that blocks beginning with C5's came with the 4-bolt mounting flange as a change- so a two-bolt C4 block wouldn't fit correctly with the later factory engine mounts

[pbf777]

You are just not getting it lol-........................

If you do a little research, ..............................

      Oh I "get it", and I'm sorry but perhaps the issue might actually be that you haven't gotten out enough, as I have processed probably half a dozen of these blocks through our shop belonging to customers over the decades (currently have a customers' "C5" example, different I know, here for among other things "cross-bolt" cap installation) and probably still have several in our storage building, these all having been purchased by us as complete engines, all having had 410 cranks in them (another reason why we would buy them back in the day ); and we didn't buy any engines/blocks that had been over-bored aka. rebuilt, so I highly doubt the cranks and pistons had been swapped in all of them,..................just not likely.    

      But as I stated previously, I shall comment no further and yield to your greater wisdom.   

      Scott.