David E

yeah i am thinking about getting a new nv5600 and maybe changing my ratios out as i have 554,000 on my truck chassis so the rear diff is worn fairly well and has some annoying play in it i had it checked and they said it is in the spider gears not the ring and pinnion so i am drive it for now . with your tune can you drive empty with good throttle response and still pull heavy like 30k lbs with out over temping the exhaust i do know my truck is from Florida and seems to run slightly different on factory setting than trucks from the north. it is built in 10/05 and i wondered if they advanced the timing from factory for emissions purposes. i have a smarty tuner on it and with the advanced timing it can rattle slightly at times they shop says it might have factory advanced timing to a small degree anyway. PS would 3.54 or 3.73 ratio be about the optimum for fue milage i have plenty of low gears i take off in 2nd most times and usually only use 1st when pulling above 22k or so

Right i beleive to now that i see it that the 13 speed doesnt make a lot of sense. i am not real good with gear ratios etc but that does look like the 10speed is the key so we will have to see what we can figure out. unless i would do the rtof909b that looks to be .73 on the over drive but either way making sure i have a good over drive is key as i would mind bringing my rpms back slightly. my brother has a 07 with the g56 and different rears and empty he can get 20 or so, where i can only get about 18

ok yeah you might be right unless the 1.00 direct in the high side of the split it looks like that is for the rt 613 the rto 613 appers to have a smaal overdrive it is showing .8 to 1 which would work eaton-transmission-specifications-catalog-en-us.pdf

yeah i found a road ranger 13 gear ratio chart for all the 13s i beleive it looks like the 613 is 1.to 1.24 in over drive if i am seeing right Eaton Fuller 13 Speed Transmission Ratios is what the page is called if you want to see it

yeah some trannies shift like you were saying but not all 13s do maybe the smaller ones are diiferent, but i drove one that had low range low1234 mid range low or (cheater gear) 5678 you get the 13 spee by splitting 5lo 5hi 6lo 6hi 7lo 7hi 8lo 8hi in high range i think maybe it was a 9513 which is rare anymore and no parts easily avalible but it may be that the 6613 will not work the same a good 10speed with over would work as well i dint decide yet. is there a way to find out the shifting pattern of the6613 aand is it oerdrive or not

Yeah i thought about that i dont think that will be a big deal for me i think i have 410 rears i am running 1750ish at 55 and 2200? at 65 or so i thought if i can get a 13 speed i coul split it down into smaller steps to keep my egts and rpms in the sweet spot i do have an egt guage

no i was thinking a 10 0r 13 speed if you get the 13 speed you can switch things around inside and get a double overdrive, that is at least if its an over drive to start with but i havent yet decided if i am for sure going to do it i really like shifting the big trannies much better they can float shift that is nice in my opinion

does anny know of someone or want to do the adapter for me to bolt a road ranger to a 5.9 with the fctory bell housing