Later large thrust main bearings

Should one always use the larger thrust main bearings found on later big blocks? I'm building a motor for a manual transmission car, and I'm thinking the larger thrust area is a good thing if it fits your block.

If you're working with a later production block that can accept the larger flange diameter, makes sense to me.

If you can't find a large flange thrust bearing that gives the clearance you want don't worry. People ran the small thrust in Top Fuel for years.

I think you have to run the later center main on all the later blocks due to the way Mopar machine that center main in the block and in the cap, I don't think you can run an early center main bearing in a 1973/1974 440 and later block, maybe so

I'm more concerned about longevity with the clutch pushing on the crank on a street car.

How about all the manual trans equipped engines with the early thrust - they never seemed to have any issues.
And all the race cars with the small thrust, no issues there either.

If you have the large thrust block, go for it.

Cab, the small thrust main will fit in a large thrust main crank line .

Will you be idling for hours with your foot on the clutch ?

If you can find the large thrust mains and they fit the block then use them . I've seen people say to file a very small angle (chamfer) on the rear side of the center main, in a 4 speed car, from the groove in the middle of the main bearing so it sends some pressurized oil to the rear thrust surface. I've done it to a couple engine I have in the works, and to a friends engine and didn't see any oil pressure issue because of it .

Same principle from back in the day when the number 1 main bearing had a chamfer on the parting line to spray oil on the timing chain.

I did not know that , thanks

and thanks, chamfer was the word I was looking for