Recently I was trying to find a compression tester for my D47u. I tried everyplace I could find that sold that sort of equipment. Nobody even had a suggestion where to find one. I posted here and a couple other places. I got nothing. I came up with a solution. I thought I'd post it here for anyone who may have the same issue in the future. I already had a diesel compression tester. Nothing fancy, got it on Amazon for just under $40.00. It comes with several adapters, none to fit a D315.I made a bracket so the adapter that fits a Perkins and I think also the D4400 can be used. And after cutting a slot, it fits in the case the tester came in. I used a short piece of angle from an old bed frame, 4" angle grinder, a ruler , and a piece of soap stone. There are two pieces which bolt onto the head using the studs on each side of the injectors. The two pieces are mirror images. I'm posting a crude drawing with the measurements,and a picture of it installed. Hope this might help someone.

I'm curious to know what compression readings you got?
Thanks

I questioned it myself. I was actually planning on having to remake it. I had a heavier piece of angle I was going to use. I forgot to put it in the truck. Figured I'd try it with that to get the angle right, and see if it was worthwhile doing it. Would have done it a bit neater job if I thought it wasn't going to buckle. However it worked pretty damn good. The one end pushed against the rocker arm portion of the head. That seemed to brace it a bit. Wouldn't hurt to use heavier gauge steel. Although anything much bigger might be difficult to get in there. 

I got around 380 lb . I didn't try adding oil to see it it increased. I didn't have any oil with me. It was sitting in a field. And I didn't want to get oil because it was almost dark. And I saw the dead cylinder was higher than one of the firing cylinders. So I got the information I really need.