I haven’t been on the forum in a while and I have done a little research, but I haven’t been able to find exactly what I am looking for. I have a 2001 5.9 quad cab short bed sitting on 35s. I am going to be getting 4.88 gears in the next two weeks. Now to my question. I am wanting to do some engine upgrades to get my torque up. I know that the engine is restricted by the intake, so I believe that a 50-52 mm TB with a new intake manifold would be a good place to start. What intake manifold is the best for better low end torque? I am currently running a 40 series Flowmaster 2.5” single out. Basically I would like some suggestions on what would be best for low end torque. As well as what not to do, I defiantly don’t want to hurt my torque.
Thanks a lot in advance
Phil

 

Are you planning on going taller with the tires in the future. The reason I ask is that a 4.88 seems to be a high gear if running down the road a lot. I just installed a set of 4.56's with my half worn 35's and the change is great. I drive a lot on the interstate and any higher gear would have put my RPM's close to where they were with the 3.55's and no O/D at 70MPH. Just something to consider if you haven't already done so.

70 MPH with 3.55 and 31.5" tire 1828 RPM Stock

70 MPH with 3.55 and 35" tire 1646 RPM
70 MPH with 3.55 and no O/D 2385 RPM
70 MPH with 4.56 and 35" tire 2114 RPM
70 MPH with 4.88 and 35" tire 2262 RPM

 

I have been tossing up between 4.56 and 4.88 gears. Right now I am running around with OD off all the time. I also am tossing around going to 36-37 inch tires. I know that I shouldn't because I tow a lot, but I am still considering it. I guess that I need to decided that prior to purchasing gears. How does yours tow with the 4.56s?
Phil

 

Just got them done a few weeks ago, so I haven't pulled anything yet. Ran around town to break in the gears the first week. Was great. Then last week on the interstate to work all week. Running around 2100 to 2200RPM's running in the left lane. Feels like I installed a shift kit with all the new power. Great to have the power back. Before, I also was unable to use O/D, and the highway was 2500 to 2800 keeping with the left lane. The only lane to drive in. Right now I was debating on another 3" of lift. I have a 5" drop reciever and am concerned with going to a 8" drop pulling a 16' enclosed trailer. 37 inch tires would put me around 2000 RPM's and 38" would be around 1947 RPM. Then would need to consider the tire sway. Decissions?????????

 

I am running a 10 inch drop receiver right now to pull our car trailer, boat trailer and camper, all of which sit fairly low to the ground. I am planning on going to a goose neck and I know it can be hard to find one to work with a truck with a lot of lift. I know of a guy pulling a goose neck with 37s though. I still am not sure what I am going to go with. I would like to find out some of the best ways to get some more torque out of the 360 also. 4.56s sound like they would work well with 35s-37s anyway. I’m not going to be pulling a dozer or backhoe but need the torque for the hills with the CJ on the back.
Phil

 

how much lift do you have?? looks like a 6 inch maybe?? 3 inch sus. and 3 inch body.. or a 5 inch suspension lift??

 

nvm.. forgot to read your signature thing hah.. i have a 3 inch now and plan on getting a 3 inch body lift too and 35's.. so i was just wondering what it'll look like.. but yeah.. cold air intake (k&n.. airraid.. ), they recommend a 52mm tb with a 360.. everyone here will say a 52mm fastman tb.. maybe a new exhaust system.. new headers.. high flow cats and dual exhaust.. hypertech programmer would really help too with a low temp stat

 

Thanks a lot man. Did you notice much with the hypertech? I figure since you are running 93 that you did. As far as everything else goes, that’s basically what I was thinking, anything you can bolt on. I just wanted to be certain that none of it would hurt my torque. Thanks again,
Phil

 

If you're going for low-end torque, you don't want to open everything up...at least not too much. Especially the exhaust. The more you open it up, the more it moves your peak up in the powerband.

Just a suggestion

 

Good point about opening things up. Currently I have a 2.5” 40 series single out flowmaster. Are headers going to open things up to much? If not headers then what about a high flow cat. As far as intake goes, I was planning on a 50-52mm fastman, it is my DD so I was considering the 52mm for that, but I do tow often, so the 50 would be better for that. And then most likely a cold air intake.
What ya think?