K, I put 315/75 tires (35x12.50s), and supposedly got 4.56s put in. I say supposedly, becuase I dont notice a difference. Originally I had 33s with 3.55. True, Im still in breakin period so Im not mashin on it. But I thought I would have "idle up hills", kind of power. Wut do yall think?

Roy

 

4.56's are like the stock tire gear ratio.. if you wanted more power you needed to go with 4.88's theres a chart on it ill have to find it!

 

heres the page with the chart!

http://www.4lo.com/calc/geartable.htm

 

Yea so did i. Then i realized i was crazy to think that a 7000 pound truck with 95 pounds of weight at each axle would be able to idle up hills. Watch your rpms when you hit the gas, even in breakin. Your truck isnt struggling. Feel the truck at around 40-45 where it shifts into 4th gear. give it a little bit of gas, you can really feel it! Granted I have 4.88's and 35's, but there is only a 6% difference in power/rpms between the two. You came in with your expectations too high (as did I). I felt let down for about 3 days, then i realized how much more fun my truck was to drive!!!!!

 

x2 i cant wait to get my lift and tires so i can regear! hahaha

 

Same thing recently happened to me. I went from 3.55 and 33's to 4.10's. At first I was disappointed. I thought my truck with a 4.6 would be supercharged. LOL After several days I have noticed that I can cruise around in OD much easier. The problem is this engine just doesn't make power right off the line. It needs to be in a certain RPM range and I can't change that.

 

yea, I think i did have too high of expectations. And also, now that im not being so 'easy' on the throttle, I am noticing more power. Thanks for the reassurance.

 

I think sometimes people are looking for too much in gears. Had you not changed tire size and went to the 4.56's you most likely would have felt a nice seat of the pants upgrade. You have to keep in perspective that your adding 2 inches of tire and adding weight when you up the tire size. If you can do that and keep the same performance your actually ahead considering the large amount of unsprung weight your adding.

I'm doing 35's and 4.56's, coming from 3.55's and 31's. My expectations are to come out atleast even in pulling power. If I can add that much unsprung weight and not lose anything I'll be happy.

Now when I changed from 3.55's to 4.10's in my mustang and didn't add any tire/wheel weight it was a noticeable upgrade. I just don't expect that same upgrade on a heavy, big tired truck. (especially with my little 4.6 )

 

I had doubts that he even put the 4:10's in at first. A guy told me to jack up the rear and count how many times the driveshaft spins in one tire rotation. Mine spun 4 times so I knew I didn't still have the 3.55's in and that he put 4:10 in.

 

One thing you all need to remember when you change the tire size to taller changes the gear ratio.
Example: 28” tall and 4.10 = true 4.10
31” tall and 4.10 = about a 3.97 gear.
This only and example and the calculations are not exact.

 

If you went from 33 and 3.55s to 35 and 4.56 you truck should feel a little faster. You have the equivalent of going from 3.55 to 3.92 gears with stock 255/70 R16 tires. Granted you are not going to beat up on Stangs but it should not shift out of OD going up the overpass on the highway. As was mentioned the extra weight will come into play but the diff in weight between 33s and 35s is not a lot. You have already paid the weight penalty going to the 33s.

JMC

 

hmmm.... some good points. Im feelin better bout the $1275 i spent. I mean, I got the lift and tires not for appereance but for performance offroad, so when I thought I lost performance, I got unsure. But Im satisfied. Would have went 4.88s, but seein that my truck is my ONLY vehicle, driving to school and work everyday, didnt think it would be to practicle.

I got a 4.6L, nothin wrong with that... Or is there, do I have another thing to be unsure about?!!??! HAHA, just kiddin.

Thanks again.

Roy

 

4.6 is a great motor with enough power to do anything you ask of it.

 

Nothing wrong with the 4.6, it will get me everywhere I need to go and pull my motorcycles around. It just won't get me over those mountain passes as fast as other trucks sometimes.

I don't need a race truck though, just need something that will get me and my bikes where I want to go

 

Got a PI 4.6 4x4 with 3:55's and 5-speed tranny with 33's. I was going to swap in some 4.10's because I don't see going up in tire size, and the 5-speed's final ratio is 0.8 vs. the auto 0.7 so it would be like running 4.50's. Now I'm thinking about doing 4.56's, but that puts me about 5.00. I spend most of my time doing 75 - 80 mph. so I'm not sure which way to go. Too bad reverse 4.30's are hard to come by.

For $2,300 I expect to see some performance, and you only have 1 shot at it unless you're loaded.