one54ton

My mileage is ok at best. Im definatly thinking of swapping out my 4.10s for 3.55s. How much better mileage should I expect. I also heard 3.55s are better in the 1/4 mile. Is this true?

rebal

my 01 HO will hit 24MPG (hand calked) all day I have gotten 26 1 time but if I keep it at 62mph that seems to be the sweet spot

the 01 SO has a service body on it and gets 15 mpg at 10k gvw
both have 3.54s

one54ton

I dunno what I get but im guessing around 16 with 4.10s

jta

that is about the best I have got.

J BODY

With a stock tire size you would enjoy the benefits of the 3.55. With the tire size you are at I would stick with the 4.10.

Sea Bass

Yeah.. I have 35's with 3.55's and I hate it. At 2000 rmp's I'm around 82mph. I can't pull any kind of hill even empty @ 60-65 mph. My egt's climb pretty good. I'm wanting to go down to 4.10's in a bad way. Stay there!!! Don't do it!!

How fast you going at 2000 rpm's? 65?

RowJ

Sea Bass is right...if your stock, or close to it.
I love my 3.55/35" combo....and I love 2000 rpm at 80 mph. But it does take HP to compensate for what amounts to a tall rear end.

I get high 16's for mileage around town...and can do 18 in a trip at 75 mph. You can't compare an auto to an HO, or any manual. It's apples & oranges.

I would think 35" tires on a 4.10 rear end might be just about right for the drag strip. I just did a 1.75 sec 60' yesterday (see signature).... so I can't complain about my set up .... but I still think I geared a little high??

I'm guessing 3000+ rpm at 110 mph would be close to perfect for qtr mile racing, if that helps you decide. I'm below that..... at 2800 rpm's.

RJ

mooseman

Id stick with the 410s. I just did the swap from 355s to 410s and love the new found power turning the 35s. My mileage went up around town and stayed the same on the highway @ 75-85. Also while towing my egts have dropped a very noticeable amount.
mooseman

AggieJustin

How much was the swap from 3.55s to 4.10s?

mooseman

I cost me a little under 400.00 for everything. I have a buddy that manages a six states shop that does this sort of thing for a living so he was able to hook me up real well.
Average price with parts and labor is around 1000.00.
Mooseman

I SPEED

I just went from 3:55 to 4:10 also. With a 315 tire the truck slowed in the 1/4. Went from a 14.2 to a 14.6.

I have since corrected that with a set of injectors.
Check sig for updated ETs.

Sea Bass

Your times got slower? I sure would have thought it would have been the other way around.

How did your speed compare at the end of the track?

I SPEED

Yup, lost the top end with the 4:10s. MPH was 94 when it went 14.6.