Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
NAXJA is having its 18th annual March Membership Drive!!! Everyone who joins or renews during March will be entered into a drawing! More Information -
Join/Renew
Welcome to the new NAXJA Forum!
If your password does not work, please use "Forgot your password?" link on the log-in page.
Please feel free to reach out to [email protected] if we can provide any assistance.
the 4.0 is really quite bulletproof in it's stock configuration, any mods beyond that are only going to give you little bits if improvement and that's debateable depending on whose opinion and what improvement you seek. I'd have to agree with MudDawg
I suggest you keep the stock cam and increase the valve lift to 0.433"/0.440" with a set of Yella Terra 1.7 ratio roller rockers (part no. YT6628). If you want more power at higher rpm, you can port the head.
Do Not buy a Crane Cam! They suck and WILL blow up. I have had two die and Dr Dyno had one die on him as well. Stick the stocker if you want a solid long life motor. I went and put in a cam from Hesco and really spent the money for it so hopefully it will last. I had a "RV" cam from Sealed Power in my old 4.0L motor and it is still running strong now in my friends 4.6L stroker. When you put the head together, make sure the spring pressure is not too high and also that there is enough clearance with the springs and cam lift. If you do go to a bigger cam, you need to do intake and exhaust mods to get the most out of it.