Hopefully I can tap into someone elses expertise on this one. Have a D343 (spacer plate block) out of a 988 87A series. Upon tear down the O-ring bores were found to be bad beyond repair. So ordered re-con block. Block arrived but with .060" counterbores cut in the freshly machined deck surface. Now why on earth would anyone cut a counterbore in a freshly cut spacer plate deck surface? Am I missing something? I realize that a deck surface can be slightly counterbored to lower a liner with too much protrusion, and that shims are available to raise a liner that is too low. According to my rough calculations, I would need approx. .062" worth of shims to correct the problem. I am not real comfortable adding that much (even though it could be done with 3 shims) and I shouldn't have to. Does anyone have an opinion on using .062" worth of shims? Also does anyone have the min. spec. for crank centerline to deck surface? Just curious if this block has been cut too much already. I may just send the block back. Thanks in advance. Steve.

I,m gussing that the top of the spacer plate block was eat out so that,s why it was cut deeper.It does sound like quite a bit but at the shop esp. with the counter bored blocks (not spacer plate) I have stacked shims to get the correct protrusion with no problems. It had to be bored deeper so it would clean up metal eat away and cracks in it.I can,t rmember anymore what size shims are available at Cat but if you keep it get the thickest shims you can and then the thinner ones to get the correct protrusion and I think you,ll be ok.I don,t have anything on the center line specs.If it is not satisfactory for you I would return it and look elsewhere.I have to keep reading your post and it sounds as if the bores were there before the top deck was surfaced so again I,d return it if it isn,t satisfactory. If you do look for another block there is a Cat dealer here in Pa. that has a used parts store so I can give you the Ph # to check if they have a block s let me know.

If I was getting a reman block I would not want that one. Most likely a previous owner or mechanic had cut those counter bores long before the outfit that remaned it got their hands on it. They are probably way below the minimum spec for the deck.
I don't see how your original block could be beyond repair? If the lower oring seating bore can not be filled to repair, then it can be rebored and sleeves installed.

The problem with sleeving is that by the time you bore oversize to clean up, the sleeve would of had to be considerably larger than the bore at the deck surface. There would be no way to get the sleeve down in there. I have had these blocks sleeved before so I know it can be done. One other thing that I forgot to mention is that where the ferrule/seal meets the block, they have filled in around each hole with what appears to be JB weld. Obviously in an attempt to repair the block where it was pitted around the holes. It looks good as it was machined afterward, but I am not real comfortable with this not having ever done it before or knowing of anyone who has done it with success. Any ideas on that? Thanks again to all. Steve.

It gets sleeved/inserted back to standard..any competent machine shop that works with big diesel blocks has access to bore inserts like those offered by IPD.

That block you bought sounds like a real pos..I'd return it for a refund and re-work the original..just my opinon.