Specifications

Oil Recommendations
There's a lot of "Hocus Pocus" on who's oil is better and Synthetic vs. "Dino" Oil. We've run Redline,
Royal Purple, Amsoil, Mobil-1, Castrol, Valvoline, and a few others just to see what would happen. What
ultimately happened was that we were a few dollars shorter in our pocket book...with the exception of the
Royal Purple oil (mileage went up .5mpg and overall engine operation was much smoother and more
responsive). If you change your oil at the recommended intervals (normally 3500-5000 miles), a good
Non-Synthetic oil won't hurt your engine one bit (unless it's low-grade "El-Cheapo" oil). If you want those
last few HP out of your engine or race your vehicle every weekend, switch over to Synthetic Oil. It will
last slightly longer in your engine but does cost more than regular oil. Which do we recommend? We're
not going to recommend any since it causes problems between vendors and personal preferences.
Spark Plug Recommendations
While the factory and factory replacement spark plugs work, the Magnum engines have shown slightly
better performance with the Autolite 3923 Spark Plugs. The Autolite 3923's are a standard tip spark plug
that is one heat range colder than stock, as compared to the extended "Special Power Tip" plugs that the
engine came with. Why the difference? A standard tip plug is less susceptible to detonation, is a good
replacement for modified Magnum engines, and work very well with modified engines as well...especially
when using Nitrous or a Supercharger. In some cases, the Autolite 3923's also showed a 4-5HP difference
at the rear wheels on the Dyno. (The test was performed with new OEM Spark plugs vs. the Autolite
3923's. No changes to the engine and the plugs were tested on the same day under the same conditions.)
O2 Sensor Replacement
The O2 sensor(s) on your vehicle are designed to sense Oxygen in the exhaust stream. When they sense
too much "air", they richen up the mixture and when they don't sense enough "air", they lean out the fuel
mixture. Under normal conditions, they should last you 60-80K miles. However, we all drive in varying
traffic conditions so the life of the O2 sensor is diminished. We recommend that you change the O2
sensor(s) every 60K miles to keep your engine running in optimal condition. (This includes the regular
service intervals and tune-up schedules.)
Which exhaust system is better?
Many people have debated this and a lot of it has to do with loyalty to a company label. We have
personally run Dynomax, MagnaFlow, Flowmaster, Ravin, JBA mufflers and exhaust systems, and found
that the single exit systems were slightly better than the dual exit systems...on the Dyno and at the track.
The reason for this is that on a single exit system, the exhaust pulses don't fight each other on the exit.
They all sounded good, all performed much better than stock, and all had a slightly different price tag on
them. Which one should you use? The one that sounds and looks the best to you. We all have different
tastes when it comes to our idea of what sound good so base your opinion on the sound quality...not the
advertised flow ratings or who sponsors what race.
A brief note on the advertised flow ratings of mufflers: Mufflers are rated on a Flow bench. This uses a
regulated flow rather than the random pulses found in the exhaust stream which doesn't say anything in
regards to the performance quality on street driven (or weekend racer) vehicles. So why buy a 1000+CFM