Possible head/valve problem

[Downthehaul]

I have a prostar with an isx, model number says 435st, is that an 871? I can’t find that distinction any damn where.

I did an overhead set according to rawze’s video and the cummins manual. When I read in the cummins book about the detent on the jake brake I measured it, and was alarmed. Here are the figures on the detent as measured with a feeler guage.

Cylinder 1: .040-.041
Cylinder. 2: .047-.048
Cylinder 3: .035-.036
Cylinder 4: .030-.031
Cylinder 5: .032-.033
Cylinder 6: .027-.028

The way I got these was setting the jake rocker to .276, then putting the guage in at detent position at increasing thickness until I felt greater than zero resistance.

I’m concerned that they are in such a wide range. The book says .025- .110, but should they all be similar? Anyone have experience with this? I read a rawze post that says if they get lower than .028-.030 the head is shot and needs to be replaced. This engine was rebuilt before I bought it at 503,000 but the head was NOT replaced. It now has 707,000.

It’s at cummins right now and they’re doing the overhead, I’m waiting to hear back. Hope I’m mistaken somehow.

And if anyone knows where to find a list of spn codes, specifically 1747 and 502807, that would be great. Can’t find those two anywhere.