Higher running temps after 2.79 to 3.80 swap

You misunderstood...

I didn't mean the gears caused a lean condition...
I said that it sounds like he is lean in the rpm range that he is now spending a lot of time in. Whereas before, he may not have noticed because he cruised at a much lower rpm with the previous gears.
Therefore, the gears didn't cause a lean condition, they just have magnified a pre-existing lean condition.
Dave

Btw: Watch the temp range of your plugs on a performance engine. Too high a heat range for your combo/cruise rpm can cause overheating.

 

i had this problem on my chevvy truck. it ended up being the steam holes in the head gasket swelled up and blocked the coolant from going into the heads.just a thought

 

Man, I wish this thread would not have gotten so long...

Lots of good suggestions. This all leaves me with at least three things to work on. And after rebuilding the rearend ($400) the wife is kinda gettin upset with the extra spending on a "worthless" project.
1) New water pump
2) New hi-performance thermostat (cheap)
3) Metering rods, which I have needed since the beginning
possibly 4) new radiator.

One thing I noticed today. Each time I stop the car and it cools down, I drain out my garage-designed PVC overflow tank. It usually has a little "crud" in the bottom. I have very recently changed the fluid for at least the third time, and each time, I put a water hose in the radiator and let it run through until clean water comes out the bottom. One time, I even added some "special" additive that was supposed to clean out the deposits throughout the engine (made by prestone, so I trusted it). This is a very low mileage engine, 55k total, and all of these modifications have been done within the last 1000 miles, more like the last 500 miles.

The crud = brown water that sinks to the bottom of the bucket that catches the coolant that is drained, or that sits at the bottom of the overflow. Not solid or chunky, but just a brown-dark discolored liquid, and it tries to stick to the container when I dump it, and requires two rinses with water to come off.

If this was at the top of the container, I would think "oil" and blown head gasket, but it is more like a light sludge that collects at the bottom.

Is this a sign of some other symptom, that is just coincidentally occurring at the time of the rearend rebuild, or is exacerbated by the increased RPMs?

(At this point, I expect someone to submit a "miracle" reply that will solve all my problems, and those of many others with similar coolant issues, and will cost less than $10, AND will make my engine run at 180, regardless of temperature and driving conditions!)

 

1. It's not a "worthless project", at least no one here thinks so.

2. Personally, I think you need a new radiator (a 3-row) and a complete flushing of the entire system. Some coolant stays in the block even when the radiator is completely drained. Get a shroud as well if possible.

3. Don't get discouraged. There's a logical solution to your problem...

 

Many of my street rod friends that run Ford engines also run a cooling system filter in the upper radiator hose. Sounds like you need one as well. A new radiator is not the issue. That stuff is coming from the block, but a rear end change would not cause this. Sorry, no magic answer here.

 

the "worthless" was my wife's quote, definitely not mine.

 

I am starting a new thread...See "Hot new thread, not cooling"