So I put it (auto) in first, and just mashed on it. It just kept on revvin past 3k and right into the red. I stopped at about 2300. So is this something that any of our beloved cummins will do? I am kinda hopin yall might say something like "That wont happen unless your governer springs have been upgraded." That would be a good thing. I sure wish I could find out who the previous owner was.

 

bigbaddiesel,<br><br>Did you mean 3300. If so you are right. It should not hit 3300 unless the governer springs have been changed. When mine was still stock i could barely get to 2300 or so.

 

Thats sweet!!!! So what does it mean? Does it hurt it to go that high? what can I do with it? Is that a precurser to another upgrade? I only get 13.5 mpg. I had to have the fuel plate slid back a little to pass emmissions. The egts dont ever get high while im just driving around. Thanks for letting me know.

 

Id say, if you can reach 3k with your truck, then you have upgraded gov springs. <br>A stock truck defuels around 2300 to 2500.<br><br>There is a point where you will/may want to look at changing your valve springs to higher spring rate.<br>At some point, the valves will float if you dont change the valve springs.<br>I know that valve spring upgrades are required when you start pushing these engines to 4k.<br>But Im not sure about 3k.<br><br>Rich.

 

For 4k you need the heavier springs to alleviate valve bounce and the accompanying harmonics at the increased rev limit. You can do the 4k GSK and not do the valve springs if you are disciplined enough to keep the loud pedal under control (yeah, right). If you are going to put an exhaust brake on at any time in the future you might as well go ahead and install the heavier springs as you will have to have them for the brake, anyway.<br><br>The 3k GSK will still stress the springs some but not as bad. If the motor is extremely high miles you probably need the heavier springs, if normal miles the originals will hold.

 

thanks for all the info. I dont really ever drive it at that high of rpm anyhow. I guess its good for pullin up a long hill. The tranny just slams into the next gear when i go from say 1 - 2. It just doesnt feel to good.

 

I have got a freind that bought a 97 brand new and straight from the factory it would rev to 3300. Funny thing though you would always have to crank it more than most 12valves to get it to start. When I put my 3 gsk's in I got the springs to tight and it became the same way but I learned if you just depress the throttle the slightest amount it would fire right up like normal. So I told my freind to try this and it did the same it would fire right up with a little throttle pressure. Matt

 

ill have to try that. From the sound of it, most 12ers fire after 1/2 a crank. Mine has to turn a couple of time for it fires up. thanks for the tip.

 

i've hit 3500 in neutral with my 3k gsk...i wont go any further. i often hold it in 3rd until around 70mph at 3200rpms until i let it shift to OD while getting on an on ramp. 3200 is safe on the cummins with a 3000 gsk, but any further and you're starting to take chances on floating the valves (although many have said that they've hit 3500 on the dyno with no problems).<br><br>Tom

 

Well I have hit 3800 with the 4k kit and stock valves for a 94 and have not floated the valves. I know its stupid but I was almost stuck and accidentialy *ap hit that. I have the HD valves but have not had time to put them in.<br>DM01

 

Im lost, stock you can rev the motor over 3000 in 1st no load. But fueling under load to over 3000 rpms is another animal altogether that takes a GSK. ???

 

[quote author=Jrr link=board=16;threadid=12515;start=0#119037 date=1048313757]<br>Im lost, stock you can rev the motor over 3000 in 1st no load. But fueling under load to over 3000 rpms is another animal altogether that takes a GSK. ???<br>[/quote]<br><br>exactly! i could hit 3100 in neutral WOT, now i can go a lot further. my upshift from first to second was at 2800 rpms, now with the governor spring kit it is at around 3100. however the higher fueling around 2800rpms on acceleration is waaaaaay better (especially with a stock converter- you can rev it out more like a gasser to actually accelerate). like i said before, holding it in 3rd on an on-ramp and winding that motor with the stock converter gets you moving quickly. it's definately one of the best mods you can do to a 12v (as most people say).<br><br>Tom