Truck is an 86 6.9 with Banks wastegated turbo.I need to change my water pump soon as the bearings are wearing out. I'm also planning to replace the front main seal which has a slight leak. I also have a rust free radiator support I'll be installing at the same time which will simplify access.

I got to thinking that puts me halfway to changing the cam and lifters. I could go with the R&D cam, which I understand is recommended (but not required?) to change to Comp 910 springs at 1.800" installed height. It would be prudent to do this but I'm worried about access without pulling the heads. Anyone do valve springs with engine in the truck? I'm hoping I can get the intake off without removing the turbo, looks plausible.

Not sure I want to bother if I have to pull the heads as that's opening a can of worms and I'd rather just pull the engine at that point to do studs and go over everything. What do you guys think? Should I attempt this now without pulling the engine or put it off until it's convenient to pull it? Or just suck it up and pull the engine and get it all done over a weekend, assuming there isn't a can of worms with heads needing work or unobtainium parts?

 

I honestly would do it while it is out. Even look at the gaskets and cylinders and add head studs.

 

You'd have to pull the heater box as well, there isn't nearly enough room to pull pushrods, let alone to compress a valve spring.

 

Sounds like it's pretty much a pull the engine to do the cam or be fighting space constraints and maybe end up pulling it after wasting time, at which point I may as well pull it and do head studs. It runs well but is somewhat leaky and could use a proper resealing of everything (did the rear main in November though). I'd rather not open a big can of worms in the summer, so maybe getting a 7.3 (more displacement is more better, and bigger studs) to do either a re-ring, bearings and freshening up or full rebuild depending on bore taper and bottom end condition and just swap it over a weekend. Not a huge rush as I do have another truck to drive and tow with if I have to wait on heads, machine work, parts, etc. My choices as I see it...

A: Replace water pump, front main seal, reseal front cover parts with engine in truck (and replacing radiator support).

B: Pull the 6.9, the the bits in A along with new cam, valve springs, head studs, inspect main bearings and reseal oil pan. At which point it's not far from measuring taper and either hone and re-ring or do the needful if it's bad (another can of worms?). Could be done in a weekend at best or a few weeks at worst.

C: Do A to my current 6.9, but also pick up a good core 7.3 (preferably IDIT) and do either a freshening up or rebuild, whichever it needs, at my leisure and swap it in over a weekend in the fall or winter.