Gear change or cam?
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Elder User
Joined: Jan 2004
Posts: 867
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From: Eastern Pa
Gear change or cam?
Another situation with my 400 is that the power band for the cam is between 2000 and 5000. I have 3.50 gears in my 4x4 shorty. It pulls real well in that area but on the road I'm not quite touching 2000rpm at 60 mph. It probably should also have a slightly higher torque converter than the stock one. So what would be a more fun truck to drive. Doing a gear and converter change with what I've got, or changing the cam and leaving the gears and converter alone. I know which one is cheaper. but that's not my question. Which one would you think is more fun to drive. This is a for fun truck, not a daily.
Elder User
Joined: Sep 2002
Posts: 615
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From: Smithville TX.
I have a 78 Bronco with a 400. As you well know they were dogs in stock form. I installed another cam that was a little hotter and an Edelbrock streetmaster intake and a 650 Holly. This livened the 400 up considerably. But four wheeling above 10,000 feet it needed a little more low end torque. I pulled the front cover off and re indexed the cam, advancing it by 8 degrees. By advancing the cam timing it moves your torque curve to a lower RPM range, the old Bronco has done well since. Another little mod I had to make was the carb. When I would get on a very steep grade, the Bronco would flood when the fuel in the front bowl would run through the balance tube to the rear bowl and make the truck flood. I solved this by installing an adapter plate on the four barrel intake and installing a 500 CFM Holly two barrel on it.
Michelle
Chelle's 56 Hauler
Michelle
Chelle's 56 Hauler
Hotshot
Joined: Dec 2003
Posts: 18,423
Likes: 9
From: iowa
not even turning 2000 at 60, yea I think the gears would be the choice for right now, not sure how big of tires you have, but guessing you have 33in tires to get that rpm at 60, and since you said that you are only using this as a fun truck go with atleast 4.11 this will put you at a little over 2700 at 65mph which still won't hurt you too bad on just driving it around, and will make a world of difference in the what it performs. If it is truly just a toy, and/or you ever plan on putting a larger tire you could go as low as 4.88 which would give you 3200 at 65, but that is assuming the tire size.
Laughing Gas
Joined: Aug 2004
Posts: 1,138
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From: Yuba City, Ca
yeah do the gear change to a 4.10. not sure what you have axel wise but i'm assuming dana's. you'll love 4.10's with 33's. plenty of power to get it goin. you'll see a noticable difference. the 3.75's are higher which is slow at take off. these trucks aren't meant to do a hundred and ten so thats what i would do. 4.10's are the way to go!!!
1978 F-250 Ranger Explorer 4x4
351M, C6, Np205, D44 Front(not 100% sure, have issues), D60 Rear 4.10LS
Drive It Like You Stole It!!!!!!!
1978 F-250 Ranger Explorer 4x4
351M, C6, Np205, D44 Front(not 100% sure, have issues), D60 Rear 4.10LS
Drive It Like You Stole It!!!!!!!
Posting Legend
Joined: Sep 2001
Posts: 30,255
Likes: 37
All this is why you need to pick the cam for the application. Bigger is not always better!
When you drop in 4:10's the fuel mileage will drop in the toilet too. Of course with the overly large cam your mileage is probably already there. Good thing it is only a fun truck!
When you drop in 4:10's the fuel mileage will drop in the toilet too. Of course with the overly large cam your mileage is probably already there. Good thing it is only a fun truck!
Hotshot
Joined: Dec 2003
Posts: 18,423
Likes: 9
From: iowa
Actually torque his fuel economy might actually improve by dropping to 4.11, you know that, with only turning 2000 at 60 he is bogging the engine, and making it work twice as hard to get going putting 4.11 gears with 33 in tires would actually put him at the equivelant of stock gearing with stock tires.
Those cubes are thirsty at high RPM's.
