Scott, If you didn't tell the crank grinder you wanted the closer tolerances they will grind to .002, which is fine for SBC and SBF but the Buick needs closer tolerances for good oil pressure. You can't just measure one bearing at a time. Do the plastigage all at once and torque in three steps, snug, half and finally full torque in the proper sequence. Don't trust a clicker type torque wrench unless it was recently calibrated.  Check your rods too to see if they are .002 also. I just remembered that your crank was turned down to .010 on rods and mains.

Here's the crank numbers. The specs on the rods are here as well. I'm not sure what the numbers are in relation to the rods bearing tolerances. Help me understand his notations because I don't know what I'm looking at.

I'm going to redo the calculations after I get a better torque wrench. Doing them individually could throw the measurement off?

Looks like he ground close to min. specs and the bottom .0002 I think he means .002 bearing clearance. It will work but .001 to .0015 would be better. You would use 10-40 or 20-50 oil where you could have used 5-30. The only other thing you can do is have it reground .020 under and specify .001 to .0015 clearance.

So, undersized or oversized bearings wont help? In either the mains or rods.

Scott, No, undersized bearings are only available in .001, .010, .020. .030 and rarely .040.  This may be an alternative. You only need 1 sheet of .001, you only need it for the 5 main bearings. Stock 215 specs for the rods are .0015 to .002. Call them and see if you can get one sheet, you don't need a lifetime supply.

https://deckwartaperedshims.com/main-bearing-shim-installation.php

Thanks Jim, I'll call them tomorrow. But first I'll redo the plasti gauge and get all the caps torqued to spec. I'm getting a digital adapter for my torque wrench to help get an accurate reading. My wrench is pretty new but its a larger type the lower readings might be off.

Remember the main caps are numbered and have an arrow pointing to the front. The reason I mentioned the orientation of the pistons is they have to be installed that way.

I will be interested to see how you come out on oil pressure but in the past .002" bearing clearances have pretty much always resulted in sub-par performance on oil pressure and bearing life. There is a whole history involving band-aids of various types from extended gears to external lines to ultimately, thicker oil. None of which was ever completely satisfactory. Typical SBB factory bearing specs are .0008-.0012" and the rest of the system is engineered for those clearances. It's one of those things that really needs to be discussed with the crank grinder before he starts. I specify those clearances on both the mains and the rods, and I get excellent oil pressure numbers with 5w30 and even 0w20 oil.

The 3 great keys to good oil pressure are first and foremost, tight bearing clearances. Next, tight end clearances on the oil pump gears. Third, enlarging the suction diameter and the rest is cleanup. Things like chamfered edges and attention to details.

You can try shimming your bearings. It might work out OK for you. 60 or 70 years ago it was a somewhat common remedy for worn out bearings but bear in mind they aren't designed to be shimmed. Odd wear patterns could result and with those clearances you don't have any room for odd wear patterns. The best solution is to go back to the crank grinder and get it done the way it should have been done in the first place. Nobody wants to hear that, but it's the unvarnished truth. Or you can run gear oil in it, your choice. Hard as it is to hear, I know what my choice would be.

Jim

I appreciate your input. I reran the clearance checks with a new digital torque wrench and did what Jim N. had suggested which is to do all the bearings at one time and make sure the wrench is calibrated and do the proper torque sequence. The number came up to .015 on all of the mains. The crank grinder was told the clearance I needed and he marked the crank at 10 for both rods and mains. He was not a friendly guy and I'd go somewhere else if I was getting it reground.

Scott, Looks good!

Thanks, I think I screwed up on the second test. I didn't look at the caps and only cleaned off the used dried plastic gauge on the journals. When I took the caps off, there 2 lines. The original residue and the new gauge material.  I'm assuming that could cause some issues with the crush on the new plasti gauge. I may do it again to be sure.

Better than .002" for sure. But let me just ask, what is the engine's expected use? Will it be run hard, or will it be lightly treated? Expected to idle a lot, or primarily run on the highway? That could make a difference.

Jim

I'm not a burn out guy or a high rev guy. But, I want it as right as I can afford.  So my thinking is to check the rod bearing tolerances and then decide if I start over with the crank. Do you think the leftover plasti gauge on the crank caps would throw off the clearance measurement? Most of the caps still had the left over plasti gauge on them when I retested them. A clear sign I'm a rookie!

Scott, if the other ones were good I wouldn't worry about it. Check the rods, one side facing dimple in, the other dimple out as they will be installed. You can do a pair at a time on each rod journal. 35 ftlbs.

Hard to say for sure, it depends basically on where it is relative to the new test. If adjacent to it your results should be valid, especially if the old test smashes out to the new value at the same time. Best practice would be to make it perfectly clean of course. Bearing in mind that plastigage is just a second check and not a substitute for accurate measurements. You basically use it to confirm that the shop did what you asked them to do, whenever there could be a question. Best of course is to work with a shop you know you can rely on, as their measurements will almost always be better than your own. It is a little worrying that their recorded measurement was off by one decimal place.

You might base your decision on overall bearing clearances for all bearings. If you are hitting 1.5 everywhere and your rockers are in good shape you might be OK. It'd be less than ideal, so it would be a judgement call. For instance do you expect to put over 100k miles on the engine? If not, maybe don't worry too much about it. If so the extra work is probably justified. I'm not going to tell you not to fix it right, but depending on circumstances you might get by with it. How much risk are you comfortable with?

Jim

Thanks guys, I'm going to wait until i get  the rod bearing tolerances before I decide. The motor only had around 10,000 miles since it was built in 2009ish. Even though I thought it was strong, the ring failure happened after only 10,000 miles. It could have sat for several years and the restart could have done some of the rings in, who knows. In the mean time I still have to install the cam and I'm doing some freeze plugs that weren't done by the shop??

Jim N.
The way these rods and pistons are set up; the dimples face each other on each journal. I had Jons shop connect the new pistons to the existing modified rods. The slots on the top of the pistons all face the front.

Yep, with the crank blocked up on a table, I put the 4 with the dimple facing back on the right side looking at the front of the crank. They go on the front of the rod journal. The other 4 on the left, dimple facing forward. They go on the rear of the rod journal. Turn the crank and put the rod journal up and check the first pair, take those two off and turn the crank, then the next and so on.

When you say the "crank blocked on a table"; what am I doing to block it. I'm a visual guy and sometimes words don't immediately make sense. Now, I was assuming I had to install the pistons before I could measure the clearance's, Which would suck! How do you guys secure the crank on a bench to torque the rod caps down? 

Blocks of wood with the top piece having a v cut, or you could use a couple of jack stands on each end, now that I think about it. Check two rods at a time as a pair.

Similar to this guy:

https://www.youtube.com/watch?v=80gd2-wtjjM

OK, thanks Jim. I'll put something together.

I made this thing based on suggestions here, Thanks! And got the first 2 pistons checked and they're at .0015. So, will do the rest tomorrow. I've decided to redo the mains after the rods are done as I'm getting more comfortable doing it and think I screwed up the first test slightly.

Scott, Notice, on the rod caps if installed correctly there is a little boss that points at each other.

The dimple on the cap faces the same way as the rod dimple. That's how Jon set them up. On a different note.
Look at the #1 main in the pic. It's gouged.