"B" engine large thrust main bearings

[rickseeman]

I have heard complaints on various forums about the lack of availability of “B” engine main bearings. Especially “B” large thrust main bearings. I have a 1978 400 block that I thought I might work on so I figured I should see about some large thrust main bearings. I called seemingly 100 places and they had no idea what I was talking about. So I called the 2 biggest B/RB parts sellers in the country and got that “deer-in-the-headlights look”. So I said to myself, “wow, I see the problem now.” So I called a Mopar parts seller, Todd Marsh, an old geezer in North Carolina, Marsh Performance. (This guy is so old he has a flip phone, seriously.) But if you need information, one geezer is worth 10,000 19 year olds working at the Auto Zone parts counter. (Sorry if I offended anyone.) Todd had a 1980’s Clevite catalog and it had the numbers in it that I needed. Now I can get somewhere. So then I realized that I need every manufacturer's part number for this item. So I bought all the engine bearing parts catalogs that I could find from the early 80’s. (They all haven’t got here yet.) These part numbers will make it much easier for me to find the main bearings that I want. Then I started ordering main bearings to make sure that the part numbers were indeed the bearings I wanted. (They all haven’t come in yet.) So now after 7 days of looking and $500, the good news. There is no shortage of “B” large thrust main bearing sets. Standard, .010, .020, .030, even .040. And sometimes the price is very, very nice. The Federal Moguls below are $31.45 with free shipping and he has 26 sets. I prefer Clevites but the 1978 virgin 400 I tore down last week was 46 years old and had Federal Moguls in it (and they weren’t worn out) so they last pretty good. Here is a list of the part numbers I have so far.

Sealed Power MS-1347M ‘B’ discontinued large thrust full groove
Sealed Power MS-1348P “B” discontinued large thrust full groove truck
Michigan MS-1348P “B” discontinued large thrust, I assume full groove
Federal Mogul 5026M “B” discontinued large thrust full groove
Perfect Circle MS-1348P “B” discontinued large thrust I assume full groove
Clevite MS-1348P “B” discontinued large thrust full groove
Michigan R2026P “B” discontinued large thrust I assume full groove
“B” Small thrust bearing is 3.445” OD, ‘74-up Large thrust bearing is 3.691” OD

Federal Mogul 5026M STANDARD SIZE Main Bearings For Chrysler 361 400 V8 | eBay?

 

[1 Wild R/T]

I believe the issue is small thrust main bearings... Five years ago I couldn't source any anywhere... Wound up fabbing a jig so I could cut down large thrust main bearings on my lathe...

 

[69Bee]

So, after all of that, what exactly are you looking for (brand, year & size) and I can check tomorrow for you.

 

[rickseeman]

I like the Clevites MS-1348P unless they made a H bearing this size.

 

[Lefty71]

This seems like it should be a sticky, so your efforts dont get lost.

 

[4speed68rt]

What is the difference between "large" & "small" thrust bearings? When I rebuilt my 440 I just ordered bearings. That was many years ago.
Thanks

 

[rickseeman]

If your block is a 1974 or later it is cut for a "large thrust bearing". It will also take the normal thrust bearing. The large thrust bearing is not necessary in most applications but some people feel if they have a block that can use it, they want to. The picture below is of "B" engine bearings but you get the idea.

 

[pnora]

I believe it has to do with the cast crankshaft being introduced. My 74 parts manual makes this note when selecting main bearings.