Gears....
Gears.... Found a body for my Sloppy 4.8/4l80e 76 mm turbo build and want to talk gears.. The new ride is a '74 C10 SWB and it has a 12 bolt open diff with 3.73's in it. Tire height is 28.5 (315/35r20)
So the truck is going to primarily be a DD spring thru fall. I would like to get it to the track and see if I can crack 10's for bragging rights once or twice a year but I have a drag Car so not that important. My DD duties are typically suburban/urban roads around 50-60 mph max. Weekend trips could hit highway but limited to 75mph with maybe a few 80 bursts. I would also like to hit dragweek but that would be for the fun of it.
So my question
I was thinking 3.42 was the gear I wanted for a turbo ride but now that I have a 3.73 I feel like maybe I should run them.
Will I be wishing I went with a 3.42 if I keep the 3.73? I know the rpm diff is like 200 at 75mph so that is not a real big diff but will it pull or leave different??
Note I'll be installing a Eaton posi so I will be in there Just wondering if the extra cash is worth it.
So the truck is going to primarily be a DD spring thru fall. I would like to get it to the track and see if I can crack 10's for bragging rights once or twice a year but I have a drag Car so not that important. My DD duties are typically suburban/urban roads around 50-60 mph max. Weekend trips could hit highway but limited to 75mph with maybe a few 80 bursts. I would also like to hit dragweek but that would be for the fun of it.
So my question
I was thinking 3.42 was the gear I wanted for a turbo ride but now that I have a 3.73 I feel like maybe I should run them.
Will I be wishing I went with a 3.42 if I keep the 3.73? I know the rpm diff is like 200 at 75mph so that is not a real big diff but will it pull or leave different??
Note I'll be installing a Eaton posi so I will be in there Just wondering if the extra cash is worth it.
TECH Enthusiast
Joined: Dec 2017
Posts: 676
Likes: 72
I agree also because most trucks have tall tires. i ran 4.56 gears in my 95 truck with turbos. It seems like wtf but when you consider it had 35" thornbirds you see the reason. It was more like 3.55s in actual gear ratio because of the tire hieght.
TECH Enthusiast
Joined: Dec 2017
Posts: 676
Likes: 72
Gear ratio is only half the story a guy with 26" tall tires will think a 2.73 is fine so he says turbos like 2.73s. Then the next guy sticks 2.73s in but he had 29" tall drag radials and its a dog so he says bullshit. Niether is wrong and both are because it is only half the story.
Gear ratio is only half the story a guy with 26" tall tires will think a 2.73 is fine so he says turbos like 2.73s. Then the next guy sticks 2.73s in but he had 29" tall drag radials and its a dog so he says bullshit. Niether is wrong and both are because it is only half the story.
For this ride I could always go from a 28.5" tire to a 31" tire and I know it will change how it reacts.
I guess I'll save the cash and keep the 3.73 for now.
