Cylinder Compression Test Numbers
 

The truck is a 2003 hd ccsb 6.0 with 187,000 miles. Ran the truck per instructions to operating temps then ran test up to 8 revolutions per cylinder.
7 of the 8 had numbers between 230-235psi with most being 235psi. but one, #7 cylinder was down to 212. It is within 15% of the top reading but just barley. What do you guys think? Run it or rebuild it? It is a one owner truck with 5000 mile oil changes whether it needed it or not. Has had Royal Purple since around 10,000-15,000 miles. 5w20 till the mileage got up there. Now its 5w30. I will be removing the heads to replace the lifters with the ls7's. (bad lifter noise) oil pressure is looking kinda funny so oil pump, new cam plate seal and timing chain and possibly a cam is on the menu. Money is kinda tight, like everybody right now and cant really afford the 408 I was dreaming of. Can I just run this motor, with this many miles another 150,000 miles or so or will it just be a 50/50 chance it will run past 10,000. I'm looking to freshen it up with new seals and gaskets, do the items list above and maybe a 2800 stall Circle D TC depending on which cam I go with but nothing very radical. Looking for an extra 100-150 hp.... Any known combos out there that will help me reach this without building it to a 408?? At how many miles should I be looking to replace the injectors an coils?? No problem with em but not looking for issues either... Figured this might be as good as any to get at em and hopefully increase my mileage a little.:burnout:

12 hrs and 130 looks and nobody has any helpful info?? Come on guys. I thought we help each other on this site?

your talking about throwing a ton of money at an engine with 187k on it. you already have a cylinder with lower compression. i would yank the engine and clean everything up. new bearings, rings, and heads. aftermarket pistons so you dont have that damn piston slap and ls7 lifters with a 228r cam and a circle d stall.

people always have enough money to half ass it twice rather than do it right the first time.

Increasing displacement will not improve your fuel economy. Period. Bitch-slap the fool that told you that.

At 187K, those compression numbers aren't that bad at all. If you want to go on the cheap, throw a cam etc in there and run it for a while. If you have the budget, build it once, build it right, and be done with it. Since you mentioned MPG's and budget being a factor to you, I would recommend something more like a built 370.

Numbers look fine to be...throw a cam and spring set in there while you replace the lifters and youll be good to go.

Thanks for the response man.. I was not taking about saving gas with more displacement. I was referring to the injectors and coils. Sorry for the confusing ramble.
What is a good rule of thumb to replace these? and how much hp with stock units support? Since I'm not building a monster, most likely will stay stock on these for now.

If you want to keep the fuel system stock, you've got to keep the cam small-ish. The Comp 212/218 cam has been proven time & time again, and I think you'd like it with a budget friendly 2800 stall converter. Should really wake up your HD2500 CCSB, and MPG's shouldn't take too much of a hit.

Yes. Been on the fence for a week now but as greasemykey stated. I really don't wanna do this twice and no funds in the budget for a nice 408 for now. It will be my luck that #7 will take a dump in my lap!... I can squeeze this build for $2,000-2,500 with me doing the work. Keeping my crank and rods and replacing the bearings, rings and maybe a set of lq9 style pistons... Rebuild the heads. Mill em .030 should put me somewhere around 10.5-1 compression... Right?
I have a lead on a slightly used EPS cam, cheap. 223/226 604/604 113+2 Good? Bad? or ugly?

I guess what I'm really asking is, should I replace the old coils and injectors that have this many miles on it with new stock units?

For 2500 you can have the bottom end done with fresh pistons and rings/bearings ect, come in with a budget built 370. Runs some cleaner through the fuel system, as long as the truck isn't having a misfire issue I would not worry about replacing coils as of yet. Wires, yes prob so. That cam is to much for heavy truck, unless you want to run a converter in the 3200+ range.