Yeah sounds like you may have the "death flash" the ram guys are always talking about. It was an updated tune for the pcm that killed performance to compensate for a blown plenum gasket. Yeah a 5.9l w/31's should run with a new hemi off the line and spin the tires fairly easily.

 

I don't have any problems breaking my tires loose with 30" tires, 3.55 gears, and a 318

 

i can light up the tires all i want. But it just seems too slow to me. Ill be doing some serious engine mods soon to improve the low end.

 

http://www.adamsdriveshaft.com/ The go to guys on gears and transfercases. What do you want from a 5000 lb truck with less than 275hp? Found out that Iowa has no smog since I have been working here. And just so happens a 440 big block is online. Seen Viper motors and chevy small blocks stuffed. What about a big block? Side note... The addition of racing stripes made my truck faster than before.

 

Hughes racing makes a 390 stroker kit for the 5.2l and also two sizes of kits for the 5.9l, like 5 different 408 kits and a 426 stroker kit. You are pushing big block territory there. That's whats nice about the 5.x's they are long blocks. Lots of room for improvement in displacement.