I figured out 14.25 imperial mpg, not great but seem to be inline with what most 5.9 magnums get. It was also nearly -30 Celsius, drops the mileage considerably, should be able to pull high teens in warm weather. Our Challenger drops 10 mpg from Summer to the coldest part of Winter but I doubt if I will gain that much.

 

Years since I updated what has all gone on with this truck. I blew the Mr Gasket head gaskets about a year later. Went to the Felpro heavy duty head gaskets, almost twice as thick at .050", have held up fine. I also had that BWD cap and rotor fail. I swapped in the Accel cap and rotor, all good there. It helped but still had a shake at idle. I swapped in shorty headers with a JBA Y pipe, both in stainless. I finally pulled off the lousy MSD Superconductor spark plugs wires last Summer. Two were arching out, went to a 8mm plug wires with ceramic boots and last set on earth of the Champion 4436 extended electrode Truck plugs. Now the miss is gone, way more power. Also a new heater core and 205 thermostat, heat still sucks but it is a Dodge.

 

Good read. As someone who cut their teeth on Mopars..I enjoyed it.

 

Yeah, not the straight foward swap everyone said it was, a bunch of work arounds that work surprisingly well, toggle switch for OD and lock up, are two. It runs quite decent now, a combination of the new plug wires and long reach truck plugs. Even these Magnum V8's have the pistons way in the hole, probably around 8.75 to 1, not 9.6 to 1 thanks to Chrysler engineering. I may consider the 3" Dynomax cat back exhaust at some point as well. I just swapped out the broken at both ends Dynomax Super Turbo and added the leftover 2.5" Hooker Aerochamber muffler from my 88 Cutlass. It is pretty quiet now. Also bought five 31×10.5R15 Goodyear Wrangler Duramax AT tires that I studded on the factory 15x6 aluminum rims. Not the factory size, someone put on the optional size, I went with it. So much better than than last AT tires. Plenty of new chebbies stuck all around town during the last snow storm. The 3.91 Dodge 8.25" Sure Grip was definitely working that day, I made it through fine. Too bad they went to the 8" front vs the Dana 35 or it would have got a No Slip in the front too. It does truck things, marginal heat sucks, never was great. I also upgraded the tiny battery cables to 1 gauge cables, probably 8 gauge, no wonder it didn't like -40 starts. It still has 40 psi hot oil pressure with 0W30. I may switch to 5W30 Vavoline Restore and Protect year round.

 

Indeed, hadn't seen this thread previously. I used to have a '99 Dak R/T CC, purchased used w/ ~7000 miles on it in '99, it was one of those that got returned for the tow rating issue. Didn't bother me. Sold it in 2013 when we purchased the wife a new '13 SRX (had to make room). It was a great truck, but MPGs sucked (best I recorded was 17.xx pure HWY, average over my time with it was 11.9 MPG). Performance mods included a Mopar PCM, 180 deg T-stat and shaker hood w/ CAI (never go around to touching the exhaust). Also put on 275/50/17 Nitto 450 tires on the stock rims and added a shift kit (chirping 2nd gear shifts was fun). My best run at the strip (modded as described minus the shift kit) is posted on DragTimes.




At times I miss this truck, but I don't miss the low MPGs. I've driven the Gen 2 Lightnings, SRT-10 QC and a '03 HD-F150 and none felt as solid and planted in the handling department as this truck. Oh, it was hard on the front brakes and ball joints (had to replace them twice in the ~75,000 miles that were on it when I sold it), so I didn't miss that either.

 

Yeah, the mileage sucks, a few less than the 3.9 V6. The V6 was fine around town but borderline dangerous passing at highway speeds. The ball joints were done before I got the truck. I just did the pads and shoes, not done since I got the truck. I actually blew out one wheel cylinder when the self adjuster fail and it over extended. I also had to do the goofy Double Cardan joint on the front drive shaft. Those low 15's from the RT's in the 1/4 were smoking fast back then, now low 14's is the normal, crazy for big heavy trucks. This truck handles like a car in 2WD in the Summer, pretty good. The A/C compressor all seized up, cooled great till that happened. Probably going with one of my open air cleaners, probably the flow top 12×2 oval air cleaner to sound and look cool.

 

As I wait for push rods for my Olds 358, I play with this truck. I pulled off the stock air hat and filter. I bought this for the Olds, was too small for my liking but fits this 5.9 Magnum perfect. I can just get the wing nut on with the stock stud. It sure is louder at the throttle body and in the exhaust.