It's a known fact; during acceleration, cornering and braking your chassis will flex and twist. The more power you add or the stiffer the suspension, the worse it becomes. All this movement uses up valuable horsepower, decreases handling characteristics and reduces ride quality.
Our brace system bridges the front and rear sections of your frame to significantly increase its' stiffness and reduce the twisting and bending caused by suspension inputs and drivetrain torque. The system is designed for ease of installation, using all but one existing holes and OEM mounting points. Comes complete with integrated brackets for optional Driveshaft Safety Loop (STF-LCBFT03).
I just finished installing both the Stifflers Lower Chassis and Long Bar kits... I first have to say... What A Difference..!!! Total worth the time spent installing and the money spent on both kits... You don't realize how much the stock body rolls in corners and on uneven road surfaces... until it no longer does... I installed the lower chassis two weekends ago with the front brackets from the long bar kit... and I noticed the difference right away... the body and frame were held together so well for the week I drove it... but the back end felt looser them than the front without the long bars... The next weekend I tried to install the long bars amd ran into an issue... The four 5.5 inch bolts to suspend the hanges from the axle... were way too short for my 2004 Lightning... I was on able to get 5 turns of the nut onto the bolt before reaching the torquespecifications... only 1/4" of the bolt was in the nut... not good enough... if you find yourself in this situation... Do Not Return Anything..! It is so worth moving forward..! I took out the 5.5" bolts and ordered four 1/2-13 x 7" Grade 8 bolts from Fastenal ($5 each) and some more Nylon Lock nuts... and finished the installation... The launch you get is so much smoother with the long bars in combination with the lower chassis... Technically... I haven't finished Step #18 of the long bars... which was "Stand On The Gas..!!!"... well at least from a dead stop... Again... so worth putting in the extra time and effort... don't give up... get it done...
1 ) The passenger side lower control arm did not move after loosening the stock bolt... but the driverside did... itwalked out further than the front piece of the lower chassis could reach... Just jack up the front driver's side releasing the weight off the wheel... use a rubber mallet and bang the lower control arm back to where it needs to be... The instructions say to initially scratch a circle around the bolt so you can tighten it back up in its original place to keep the alignment... couldn't be done in my case... the driver's side lower control bold ended up where the cross bar would allow it... I don't think I even need to get another allignement... Feels really good where it is...
2 ) Once you have the lower chassis loosely installed... tighten bolts starting from the frame and transmission and then work inwards... I initially didn't... and there were vibrations I had to chase out...
3 ) You will need to take the rearwheels off to remove the U-blots from the suspension when installing the long bar hangers... I don't think this job can be completely done on a ride on lift..? Though I may be wrong... I performed the entire installation using ramps and jack stands crawling under the entire time... not terribly fun... but so worth it in the end...
4 ) Tightening the nuts after applying the pre-load of the long bars was tricky... you'll need a 1 1/8" wrench and most likely a "cheater bar" to get the leverage you need to tighten them...
In all and after all is said and done... I would do it again... but you'd have to pay me a grand in labor haha jk... I would say if I had to..? I would just install the lower chassis alone... not sure if I would only install the long bars..? I think the added launch from the long bars without the stability thelower chassis would be questionable... These two kits were meant to be installed together... Thank you Stifflers..! GREAT PRODUCT..!!!
And thank you as well Latemodel Restoration..!
Yes, I would recommend this item to a friend!
Was this review helpful to you?
Feels like a new ride!
Edgar O. on
I decided to start from the ground up on my L build and one of the first things I got was the Stiffler's chassis stiffing system and I am glad I did! It was very easy to install with everything bolting up to the existing holes except for one bolt on the passenger's side that requires you to drill into the frame. After it was installed I could tell the difference right away! Everything was tighter the heavy roll in the turns was drastically reduced and all the creeks from the frame were gone! I do HIGHLY recommend replacing your shocks too if you never have so, you can really feel what this system can do.
Latemodel Restoration is your #1 source for Mustang stiffler's suspension. At Innovative Performance Technologies (IPT), we combine a passion for Mustang and Ford Lightning performance with our love of innovation
to develop original new products while continually optimizing existing ones. Our degreed engineering staff has years
of product design and development experience; from the highest levels of professional open-wheel racing to OE components for both foreign and domestic auto manufacturers.
This knowledge base is now channeled into our
Stifflers brand product line-up and is reflected in the ingenuity, quality and functionality of the items we manufacture.
Our Fully Integrated Technology (FIT) SystemTM approach to chassis stiffening offers unmatched
strength and stiffness, without the need for major chassis modifications. Thorough research, analysis and
in-house testing go into the development of our products long before they are approved for customer use.
It is this relentless dedication to the pursuit of excellence which is positioning IPT and the
Stifflers line of products as an industry leader.
Products by Vehicle
Email Me When It's Back In Stock!
Email Me When It Arrives!
Upload a Picture
Upload your own picture of the F-150 SVT Lightning Stifflers Lower Chassis Brace (99-04)
Please make sure to hold your device horizontally (like a camera) rather than vertical (like a phone).
By uploading an image, you agree to give LMR.com ® permission to use it in future advertisements and promotions.