"501" engine casting?

[OldBlue67]

I checked out a couple new (to me) wrecking yards today, ended up they were totally useless , but I ran into this engine that peaked my interest. It had a backwards or mirror image 501 where the 352 usually is. I remember this coming up before but can't seem to remember what it ment. Anything interesting / worth looking into?

[FORDification]

What you're seeing is actually a mirror-image '105'. The 105 blocks have some extra cranksaddle webbing...but that's really about it. Some have said that they also have thicker cylinder walls to allow for larger overbores, but many Ford gurus say that isn't true. I've also heard that these blocks have a slightly higher nickel content...but I can't verify that right now. The 105 was simply the symbol the Michigan Casting Center (MCC) used whenever it cast an FE or FT block, as opposed to the Dearborn (DIF) foundry's "352" casting in the same spot, and was put on the 360 blocks as well as the 390 blocks. They're not rare, but a good find....they're strong blocks and a good candidate for a hi-performance rebuild.

[cobraF100]

The basic 105 blocks are nothing special as Keith has said for the most part
BUT
if it's Not an FE but a FT 361/391 105 Block then I would take the time to have it sonic checked because a Good Number of the 361/391 block were cast with the 428 heavy cylinders.

These blocks could/would be found in your bigger Trucks,Like Dump Trucks,Tow Trucks,Box Trucks like Uhaul use's.

The 361/391 Blocks also used a larger distributor hole than your 390/428 blocks,Most of these blocks are made from heavy FT/428 cylindered castings, but some FT blocks appear to have been made from standard 390 cylinders.
So looking for the larger distributor hole can help you with your search BUT still doesn't mean it will be a heavy cylindered FT casting

There's only one way to find out and thats to have it Sonic Checked
This will cost around $60-100 to have one checked.

The Block I have is a FT 391 Block that was Sonic checked and will take the 428 bore but all are not the same.


There's also a Drill Bit test that Dave Shoe came up with to use.I'll look it up and post it so it can be used if your going to spend the time trying to find a Block to Sonic Check.

[cobraF100]

"Drill Bit Test"

All Info was Provided by Dave Shoe.


A 17/64" or 16/64" is approximately the drill bit that fit's between the jackets of a 330FT, 360, 390, 410 block at the very widest spot I could find on the whole block.

A 14/64" or 13/64" drill bit is approximately the drill bit that fit's between the jackets of a 361FT/391FT, 428 reinforced "C" block at the very widest spot I could find on the whole block.

A 8/64" drill bit is approximately the drill bit that fit's between the jackets of a 427 block at the very widest spot I could find on the whole block (not actually correct, as I only quickly checked a couple gaps).

A 5/64" drill bit is approximately the drill bit that fit's between the jackets of a 427 alternate-jacket block at the very widest spot I could find on the whole block (not actually correct, as I only quickly checked a couple gaps - though I'm starting a rumor that this might be a later-type of 427 jacket).

-------

If I was going to the junkyard this week, I'd likely bring a hammer and punch to pop the core plugs out of the block, and I'd also bring along a 15/64" drill bit, as it should readily find a way to slip through the walls of a 330FT, 360/390/410 block, but would likely not fit a 361/391 or 428 casting. I don't have info on the 332/352 casting yet.

This drill bit value will most certainly change as I sample more blocks. My estimates are horribly crude at this time, but I felt it important to present the drill-bit concept to everyone, even with my insufficuent dataset.

Note also that I only refer to drill bits in "1/64" increments, as a .125" drill bit is referred to as an 8/64" drill bit. I do this so I can nickname the gaps "8", "13", "16", or whatever a block measures to, as an easy way to categorize a block.

Note that the drill bit test is a "prescreen" to determine whether the block is worthy of a sonic mapping.

I've selected a 15/64" drillbit as my basis for determining whether a block is a 360/390/410 candidate or a 406/428 candidate.

All six core plugs should be popped out of the block. Probing all reachable spaces between the cylinders, the drill bit shank (the non-fluted and non-flatted portion) should NOT fit between the cylinders at any location, high, low, or in between. If it does, there is too much water gap between cylinders, and not enough metal for a comfy (sturdy) bore out to factory 428 numbers.

If the drill bit does NOT fit, this means there is likely enough material to bore to 428 values but you've still got to sonic map the cylinders to verify core shift isn't creating thin sections in the cylinder.

This drill bit value may eventually change as more is learned, but for now 15/64" what I use.

Shoe.