360 main bearing differences by years?

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Remow2112

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I have a 72 360. Went to by main bearings and discovered that the bearings for the mains are listed by year. 71-73 then 74 and up.

I have searched on here and google and can't figure out the difference. Can someone enlighten me? (The 74 and up bearings everyone has in stock. The 71-73 no such luck.)


Thanks,
Dan...
 
thrust bearing is different...which is no. 3 main bearing...
 
Thanks for the info. I found some online and got them. I was just hoping to find them in town so I could do the bottom end this weekend.

It is kind of funny. Mopar must of still had a bunch of the older 360 bearings laying around because I have a 75 360 that has the 71-73 style bearing in it from the factory. But you can see it is cut for a larger flange.

I wonder why they changed it?


Dan...
 
It appears that the last time I did the motor (72 casting 360) I bought 74 and up bearings. They fit and seem to work fine. MY new and proper (71 - 73) bearings came yesterday. When you put the #3 (71-73 style) bearing in you can see it leaves a lot of of the machined recessed viewable. When I put my old bearing on it almost completely fills the machined area.

I will get a picture tonight. It is really starting to look like any 360 mains will work. Anybody have any insight on this? I am really curious. I could have bought the 74 and up bearings in town no problem. Had to order the 71 - 73 bearings.

This great to know because the 74 and up bearings are much cheaper.

I also have a 75 360 block laying around and the flange cut / recess on #3 appears to be the same size as the one in my 72 block.

Dan...
 
Remow2112 said:
It appears that the last time I did the motor (72 casting 360) I bought 74 and up bearings. They fit and seem to work fine. MY new and proper (71 - 73) bearings came yesterday. When you put the #3 (71-73 style) bearing in you can see it leaves a lot of of the machined recessed viewable. When I put my old bearing on it almost completely fills the machined area.

I will get a picture tonight. It is really starting to look like any 360 mains will work. Anybody have any insight on this? I am really curious. I could have bought the 74 and up bearings in town no problem. Had to order the 71 - 73 bearings.

This great to know because the 74 and up bearings are much cheaper.

I also have a 75 360 block laying around and the flange cut / recess on #3 appears to be the same size as the one in my 72 block.

Dan...
Click to expand...

Good info Dan. Thanks for sharing. If you can get a couple pics that'd be even better. I always knew there were 2 different bearing designs used but never had an old and a new block to make comparisons. I am re-building a 73 360 right now and bought the bearings for a 73. Wish I had known the 74-up bearings would have worked because they are alot cheaper and sounds like they have more surface area for thrust.

BTW: did you look at the thrust area on the crank to see how the 2 different bearings line up to it? I wonder if the thrust flange for the older 360 crank is any different? I'm using a stroker crank in mine so I have no stock stuff to do comparisons with.
 
I am interested in this too. I have a '70 casting 360 block and a '73 360 block I would love to save some money on bearings. Anyone have the low down?
 
I just found out something interesting. I looked up the bearings I bought for mine and find out they are spec'd for use in 1970-1991 engines. They are the performance 3/4 groove Speed Pro Z120M bearings. All other brands (even the perf. series) have the split in yrs. but Speed pro don't.
 
Pic 1 is a 74 and up bearing in rear and 71-73 in front.
As you can see the 74 and up has a taller thrust flange.

Pic 2 is the same bearings opposing each other. Easier to see the flange width difference.

Pic 3 A genuine 1972 360 #3 main cap. You can see the machining for the flange to sit.

Pic 4 is the 74 and up bearing on the #3 cap. You can see the the flange covers most of the recessed area on the main.

Pic 5 is a 71 - 73 bearing mounted on the same #3 cap. You can real well in this pic how much smaller the flange is.

I think that the bearing changed in 74 when they started putting 360s in A bodies. You could get a standard tranny in the old A body. Prior to 74 they only came in large c body type cars which did not come with a manual transmission. So a larger thrust surface is need when you have a manual transmission.

As a side note. I was running the pictured 74 and up bearing in my 72 360 just fine and by accident. So I think it is safe to use the 74 up bearings regardless of the year of motor, or so it appears... 8)

Dan...

Bearing1.jpg


bearing2.jpg


bearing3.jpg


bearing4.jpg


bearing5.jpg
 
check the bearing tang in the #5 main cap thats the difference
 
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