To find the original tire size, look on the door...mine came with 245, but 265 was an OPTION, just like everything else that came with these trucks, ie. 3.92 gears.

 

Thanks soooooo much for all the help! also, if it already has 4.10's, then, why the sluggish nature? I'll probably be replacing the exhaust soon, and will probably add some headders in the mix... loud pipes save lives! and I wanna hear this beast roar!

 

You don't have 4.10's unless they were installed by the previous owner which I doubt Like we said they're on on Off Roads and you'd know if you had an off road. Theres a big decal on the back and its 2" higher then regular Rams

Also they only made Off Roads in 2000 and 2001 and you have a '99 My money is on 3.55 but you can check the sticker under the hood or get your build sheet here. In the subject type build sheet http://www-5.dodge.com/wccsapp/unive...ull&category=R

 

ahhhh..... ASH was right on the money! The specc sheet under the hood said 3.55's..... so, aside from that, the cat/airfilter would probably be the next suspect for the minor power loss....

 

Here's a general list of items to look into to get a little more pep out of the truck:
1. Clogged cat - can you hear it rattle or does it get extremely hot?
2. Plenum gasket leak - If it pings or your are losing oil, that could be a problem.
3. Death flash - If your PCM (firewall, passenger side) has a sticker that says something like "Authorized re-programming", then it was re-set by the dealer. Basically they retard the engine to eliminate pinging, possibly other things are done with the program.

Do a search on these items for a better description of solutions.

Ways I got more pep out of my truck:
1. Hypertech programmer.
2. 14" x 3" round air filter (or go with K&N FIPK or other CAI)
3. Adjusted crankshaft position sensor (CKP) to advance timing. Slot the holes and slide towards the oil filter.

Many other ways available to get a little more power out of the engine. Look around the site and have fun learning.

 

So i have a 01 offroad running a leveler kit and 35s and it is sluggish as hell would 4:56 help seems as it already has 4:10's in it according to this thread. And i got a fipk kit on it and dual exhaust.

 

When towing, push that button and put it in OD/Off

 

my 99 sport with 5.9 has 3.92's and came with 245's.