These guys are professionals folks.... don't try this at home.
Seriously... I'm going to chime in with this bit of experience and what seems like common sense wisdom to me.
In daily driving, if you like to go easy on your motors like I do, they are going to last a long time, have very little wear, get better economy, and are in general better health than something that is being stressed to the max every day. However, that said, it's a lot like people and exersize. If your heart rate never gets over 100, and you do something strenuous that pushes it there, you may just find out your not in quite as good a shape as you thought. Case in point... The Night Moose. There is no reason to rev that thing out over 2K. Ever. It's so light, it just scoots along in overdrive from a virtual stand still. But, we were at the rally and my son wanted to dyno it. Against my better judgement, I said OK. Sure. Cause' I was curious too. On the dyno I saw one thing I didn't like, and heard something I didn't like after it was over. There was oil flying out of the bell housing, and it had a tick the rest of the day after the test. The oil turned out to be a weak rear main seal, and the tick came from an injector that gave out on the dyno. Lesson learned.... if you have an engine that never sees high RPM's, don't decide it's time to show it them if your far from home. The valve springs in the Moose Truck are 27 years old, and they spend a LOT of time not moving. There are some springs that probably have spent most of their life compressed. Given the above, do you SERIOUSLY think it would be a good idea for me to take it to 3300? I think not. So I've started shopping for new valve springs, and 7.3 style rocker arms. BTW, Ford wants $123 a pair for rocker arms. Anybody know where to get them cheaper?
I've said this before, but I will say it again. Everything has a life span, 4 strokes of the cylinder is 1 cycle. An injector fires once in every cycle. And 1 cycle is 2 rotations of the crank. So for every RPM, it is that divided by 2 for the number of cycles per minute. At 2000 RPM, that's 1000 cycles. That's also 1000 injections PER INJECTOR per minute. If your supplying say 20CC per 1000 injections per cylinder to maintain highway speed, that's 160CC's per minute. At 60 miles per hour, that is 9600 CC's per hour, or about 2.5 gallons. So your burning 2.5 gallons on flat level ground per hour. Now, if you cut your RPM's by 500, even if you have to increase throttle slightly, say to 25CC's, that works out to 750 injections per injector per minute. That's 150CC's per minute, or 9000 CC's per hour, or about 2.3 gallons. So your looking at a MPG difference of about 2 MPG. WHY would you want to spin your motor so fast, that all it does is increase wear and waste fuel? Even at 60 MPH, say you have 5CC's being injected going downhill with your foot off the throttle. That's a difference of 40cc at 2000 RPM versus 30cc at 1500 RPM. That's a difference of .6 gallons versus .47 per hour, just going downhill! For those wishing to check my math, or play with the numbers a little more, my formula is injector CC's per 1000 strokes divided by 1000 to find the cc per stroke, times the RPM/2 times 8 (number of cylinders) to give total CC per minute.
and i have seen the new motor get to 42-4300 but it was an accident i was doing a burn out then i poped the clutch into second gear and kept burning out and held it to the floor and carryed it up the road and when i went to let off it kept revving
I went to SoCal with another board member on here a few years back...he was afraid to shift his truck any higher than 1800 or so RPM 
and he lugged his engine nearly constantly. When I got behind the wheel, I shifted at closer to 2500 or 2700 RPM and picked up 2 mpg 
hope this helps some!! 
