Got questions?

            We’ve got the answers—Mondays when the Summit Racing tech department tackles your automotive-related conundrums. This week, we offer advice for restoring a worn suspension and setting valve lash.


From: Carlos Callahan • Stockton, CA

Q: My Mustang’s suspension system is getting stiffer as it gets older. It’s a 1991 LX 5.0L with an AOD transmission. Can the front springs be swapped for softer springs? I don’t use it for racing or anything; it’s mainly just a cruiser. I would gladly give up the stiff feel for a smoother, cushion-like ride. Thanks for all of your help!


A: The stiffer ride can be caused by either sagging coil springs or worn shocks. Next time you head out for a cruise, check to see if your Mustang is sitting lower in the front end. If it’s lower, you’ll need to replace the coil springs. If it’s pretty level, then the shocks need replaced instead.


When it comes to Mustang coil springs, you’ve got two choices—stock replacement or lowering springs. Lowering springs will stiffen your ride even more while reducing fender gap, but stock replacement springs will provide the ride you’re looking for. Equip your Mustang with some Moog Replacement Coil Springs (MOG-8598 and MOG-8621) to smooth out your suspension.


If you need shocks, your best bet is with some Monroe Sensa-Tracs (MON-71828ST and MON-71803ST). They have an advanced design that rapidly responds to changing road and weight conditions for better handling and ride quality.


From: Kenneth Edwards • Monticello, KY

Q: I have a Chevy 400 small block with flat top pistons, double hump heads, and several Summit Racing parts, including roller rockers and a hydraulic cam and lifter kit. It also has an MSD 6A ignition box, a Holley 750 carburetor, and a Holley dual plane intake manifold. What is the best way to set the valve lash on this part combination?


A: When adjusting valves on a hydraulic camshaft engine, you need to make sure the lifter is on the base circle of the cam. After that, you should tighten down the rocker arm until all the up and down pushrod free play is gone. This is known as zero lash. Then continue to tighten the rocker an extra half to three-quarters of a turn. Repeat these steps for every valve. The main goal is to make sure the valve that is being adjusted is on the base circle of the camshaft.

If you need tools to conquer this project, visit the Tools & Shop Equipment department on Also, check out this video from COMP Cams—it takes you through the valve lash adjustment process step by step!



Author: David Fuller

David Fuller is OnAllCylinders' managing editor. During his 20-year career in the auto industry, he has covered a variety of races, shows, and industry events and has authored articles for multiple magazines. He has also partnered with mainstream and trade publications on a wide range of editorial projects. In 2012, he helped establish OnAllCylinders, where he enjoys covering all facets of hot rodding and racing.