Should I do this mod? What are some downfalls of this? I still want to be able to pull with the truck still and keeps it reliablitlty. Also will this make me lose any of that pin your head back lowend torque? Will it change my powerband? I do not want this to happen i would like to extend the powerband. Anyone with any info on this would be much appreciated!!<br>Thanks<br>-Ian

 

97CTD<br><br>The gov springs will change the fueling charactoristics of the pump ..... allowing the rack to continue to fuel. The stock springs give way too quickly to the flyweights. <br><br>What other mods do you already have? Adding the 4K springs requires going to heavier valve springs - which you don't have to do with the 3K springs. <br><br>Tell us more about what you have and what you are looking to get out of the engine ....<br><br>Keith

 

I realize i will need new valve springs and what i want is an extended powerband it seems that as soon as tha tbad boy starts puttin the power down you have to shift i want a longer burst of power in each gear! I still want to be able to pull a load with the truck also yet i want to achieve around 400-450 RWHP as well is that possible? My mods as of now are few but they help! K&amp;N open element, gutted AFC, silencer ring removed, straight pipe exhaust, waste gate disabled and torque plate slid all the way foward.

 

I have the 4GSK, and I love it however i have not put the heavy duty valve springs in. If you run past 3400 you will need them, I do not run past that. Anyhow the other draw back is if you pull a trailer that pulls crappy it will buck at least my does. We have some trailers at the office and they buck when I have a load on them. The pedal is going to be touchy&lt;---is that right anyhow if I had to do it all over again, oh yea no regrets Thanks Don<br>

 

i myself will be getting the 3k within the next couple weeks. after talking to numerous people (after wanting the 4k), it's really a new level on the engine. running it up to or beyond 4100rpms is pushing stock limits (besides the upgraded valve springs of course). <br><br>just to compare, a 94 putting out less power than me (with the same mods-but smaller pump) was beating me by a full second in the 1/4 mile. i can *rarely* hit 1150 degrees and he was easily hitting 1400 degrees going down the track.

 

I have the 4K springs without the heavy valve springs and so far it has not been a problem. The only time I get close to 3400-3500 rpm is when Mustang Gts need an attitude adjustment. I tow a 6000lb TT and notice no difference in towing drivability except I can push it farther in each gear if needed. If the high RPM limit of the 4k springs is an issue, its better to have it and not use it than not have and have to do it again later because you wish you had. The bottom end torque doesnt seem to be effected but with 890 ftlbs I may not have noticed it was missing.