Sbc 400. Eagle forged crankshaft. Anyone know what the end play is supposed to read? I heard the 400 is different from other sbc's. Also, can you school me on the best way to set it? What if any mains are tightened down before taking the reading? Thanks.

.004 to .007
For some reason, I always have to add a little clearance to the thrust face of my 400 builds. They are usually tight when I check them. I just did a 350 with a steel factory crank, and it came right in at .007. Of course this all depends on the block, crank and bearings you are using.
With the crank in the block using only the two end bearing shells, Install the end two bearings and caps.
Torque the bolts, and check end play and run out at the same time.
If it's tight, I take a piece of glass with super fine emery paper, spray it down with WD40, and clasp the bearing halves tightly together in my hand, keeping them aligned. Then sand the thrust face in a figure 8 motion. You will find that the thrust face is not perfectly flat at first, and gets better as you work it a little. Go easy until you get used to it.
I like to see no more than .001 run out in a performance engine.

Thanks much! I'm starting the build tomorrow morning and think I've got it covered with this info!

^^ same method here as 6kmile. i like .005-.007. they'll run with .010 though,, just don't want it tight....
andy

I've learned over the years that when assembling, just snug up the rear main bolts, take a block of wood and a hammer, smack the back of the crank pretty solid with the wood/hammer to make sure the bearing and cap assy. is oriented spot on. Then check your clearance.

I check the back side of the thrust faces for flashing and sometimes dress them a little. Also inspect the cap and saddle for dinks where the thrust face sits. Bump the crank back and forth a few times with the rear main loose, hold it in forward position while torquing to set the cap's axial position and this aligns the 2 thrust faces. You can also do this with Prussian Blue to get a witness of the contact pattern if it is an engine you are overly concerned with. I don't worry too much about this for most apps, I just eyeball them for daylight and rarely see any.

Also while I am doing my block cleaning I will sometimes find one that has sharp edges where the thrust would get skinned while you slip the bearing in. I don't like that and will fix it.