Questions: Heads, Injectors, IP (long)

[jcomp]

My 83 K5 has a blown head gasket and I plan on replacing the heads, injectors and injection pump when I do the head gaskets, and I would like to hear some opinions about what I should do.

Some background: I put a banks sidewinder system on it in december (working outside, no less). The head gasket (I hope that's all it is) went about 2 weeks later going up a long hill. Coolant temps reached around 210 and EGTs were below 1100 the entire time, in case anyone's curious. I live at 7700 ft and I pretty much can't go anywhere without a 9500 ft pass to go over. I plan on pulling my trailer loaded with firewood over those passes this summer, figure about 3000 lbs. I am also going to be switching to 4.88 gears to help with my high EGT problem and for off-roading. Currently, I have 4.1 gears and 37" tires. My EGTs at 70MPH in overdrive are 900-950 on a flat road with no headwind. I put on a set of smaller tires to simulate my 37s with 4.56 gears and my overdrive EGTs dropped to around 550.

Heads: I have an extra pair of 6.2 heads that I took to the machine shop today and found out they need a lot more work than I thought. Cost to rebuild: approx. $320. The shop also had some heads they could sell me, a pair of 6.2 heads and a pair of 6.5 heads. The 6.2 heads had a smaller intake valve than mine, and on the 6.5 heads both valves were smaller. They want $75 each for either the 6.5 heads or the 6.2 heads (both with valves, springs, etc). I'm leaning towards the 6.5 heads (they have 40K miles on them) for $150, but will I lose any power due to the smaller valves? Is there any benefit to 6.5 heads?

Injectors: Should I go with 6.5TD injectors? What are the advantages? If I do, will my 6.2 lines fit? I read a post on the subject, and there were opinions both ways. Is there a final word on the subject?

Injection Pump: If my EGTs are already high with my stock pump at the stock setting, should I still look for a better IP or just have mine rebuilt? Reading this forum, the DB2-4911 seems to be recommended, but will I be able to turn it down enough for my altitude?

Any advice would be appreciated, I'm kinda lost in all this.

[britannic]

Consider an intercooler to help with the air charge, at your elevation the turbo's having to work with low oxygen density.

Timing is a big factor in EGTs, where is yours set at? The 6.2L head with the smaller valves sounds like a C head, good for economy, but not power - I wouldn't recommend installing them.

Consider 6.5L heads, you'd have to rework the injector lines, or get replacements from the Diesel Depot or somewhere like that, but you'll see improved EGTs and power, because they have better chambers and I believe slightly bigger valves (check my last statement though). You'll love the 6.5LTD injectors, because they'll inject the fuel quicker for power and quicker burning.

Afterburning due to retarded timing and/or too much fuel is another factor in high EGTs, so address that as well.

[jcomp]

Thanks for your reply. I've decided to go with the 6.5 heads, they are the most economical route for me. They do have smaller valves than the 2 pairs of 6.2 heads I looked at, though. I watched the machinist measure them.

As for my timing, I don't remember what it is set at. I checked it a couple of years ago and IIRC it was way advanced but the truck started easily and ran well so I didn't readjust it. I noticed when I replaced my rear main seal (right after the turbo install) that my timing chain has a lot of slack in it. I will be replacing it and the harmonic balancer when I do the heads. What is a good timing setting to start with when I get it all put back together?

I don't really want to put an intercooler on this truck, at least not yet. I expect the banks system to function properly without it, as advertised. If my altitude is going to prevent this, then Banks is going to lose a lot of credibility in my book. However, I still have a lot to try before I start blaming anyone. Even if their sales rep told me that my 200,000 mile engine would have no problems being turboed and that is clearly not the case.