what diameter tire are you running? I pull about 2,000 on the highway with 3.42's and 29" tires

 

28" tires

 

i run 4.10s with my 4.8.... The upgrade is SOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO much better than the 3.42 i had... before my truck while cruising down the highway would kick down in to 3rd, sometime 2nd to go up a small hill doing 65mph... Now it stays in 4th with no issues at all...

 

iave been thinking about 410s but man those 342 are cool on the highway even with 20's with 6.0 really doesnt downshift at all eeven with a 2600 stall...can get a little mushy if you accelerate fast but I like it ...but i cruise around 75-85 mph and that helsp...I was thinking 4;10 would kill me cause I hated them on my HD but i had 16" tires so i dunno ...sorry bout hijacking...FYI wil be installing Laser Jammers this weekend ie Laser Interceptor these things are friggen awesome saved me ttons of tickets on the GTO ...even tels you what gun they are h[Itting you with might do a post to see whos running these

 

i actually recently bought some 4.10s for my 4.8 but wasnt sure how it would run on my truck? i was stuck between 3.73s and 4.10s but i just went bigger.. might as well... i havent put them in yet though

 

i run 4:56's with a 305-45-r22 tire, you'll love em