Author Topic: swapping from 3.08s to 3.73s how much faster??  (Read 6848 times)

Offline rick39452

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swapping from 3.08s to 3.73s how much faster??
« on: July 02, 2010, 08:53:20 PM »
Hi my names rick and ive been wondering around this site a little while and figured I would make a few post.I have an 85 chevy c10 with a 350 th350 2500 stall and 3.08 gears. As of now the truck runs around a 10 flat in the 1/8th mile and I am going to swap my gears within the next month to 3.73s, how much do yall think this will take off my time?

Offline Irish_Alley

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Re: swapping from 3.08s to 3.73s how much faster??
« Reply #1 on: July 03, 2010, 12:37:25 AM »
what are you trying to do? also you can push your truck past the mechanical capabilities and slow it down allot do you have a tach now? whats your red line at? were you at on your tach when you cross the line? whats your power band?
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Offline TexasRed

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Re: swapping from 3.08s to 3.73s how much faster??
« Reply #2 on: July 03, 2010, 12:40:55 AM »
3.73s may give you some tire slip also.

Offline VileZambonie

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Re: swapping from 3.08s to 3.73s how much faster??
« Reply #3 on: July 03, 2010, 08:19:02 AM »
You'd be better off with a 700R4 and 3.73's
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Offline rick39452

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Re: swapping from 3.08s to 3.73s how much faster??
« Reply #4 on: July 03, 2010, 09:17:08 PM »
yes I have a tach but dont remember what the rpms are when I go across the line but I know im just shifting into 3rd when I go across

Offline Irish_Alley

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Re: swapping from 3.08s to 3.73s how much faster??
« Reply #5 on: July 03, 2010, 11:22:32 PM »
x2 what vile said if your just shifting into 3rd when you cross you not using all your gears to get you up to top speed go for it not sure of the time you will get but it will be better than plain ol 10's lol
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Offline team39763

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Re: swapping from 3.08s to 3.73s how much faster??
« Reply #6 on: July 05, 2010, 12:56:38 AM »
What are the rest of your mods?

I ran my combo through that Wallace calculator and it says it'd run the same thing with 3.08 or 3.73's.  The only difference would be the finish line RPM.  I don't agree with that though.  I saw my neighbor lose to a Hemi Ram, after switching to numerically higher gears and sticky tires, he beat the Ram pretty good if I remember correctly.
« Last Edit: July 05, 2010, 01:11:32 AM by team39763 »

Offline rick39452

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Re: swapping from 3.08s to 3.73s how much faster??
« Reply #7 on: July 05, 2010, 11:30:10 AM »
dont know what the motor has in it all I know is its a 350 not sure if bored or not but I know it has 70 or 71 400 heads with a small cam holley street dominator intake and a holley 750 double pumper

Offline Irish_Alley

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Re: swapping from 3.08s to 3.73s how much faster??
« Reply #8 on: July 05, 2010, 06:09:09 PM »
I've raced or been on a pit crew for mini sprints and lets not forget sprint car games lol but if you have a gear and your not using it ie your 3rd then your going slower than if you were using it. But what you planning on doing with the truck. Do you drive it around town or plan on stepping it up to 1/4 if all your going to do is 1/8 and no driving around town I say swap it higher. But if you do use it as a day then kept the gears.
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Offline Swims350

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Re: swapping from 3.08s to 3.73s how much faster??
« Reply #9 on: July 05, 2010, 09:31:06 PM »
I'd step up from 3.08 anyday junk gears IMo and worthless. Yea they might be decent gears to save some highway rpm's and gas mileage MAYBE, but they aint no hot rod, race truck, performance setup.

I tell ya what we got a set of 3.90's to go in our 84, about the same motor, pretty mild and a th350 with a stock convertor, and it NEVER sees the track, only daily driving and some highway rarely.
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Offline Irish_Alley

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Re: swapping from 3.08s to 3.73s how much faster??
« Reply #10 on: July 05, 2010, 11:55:13 PM »
your looking at about 16s in the 1/4 wich is what like 90mph?. like i said before if you plan on racing it yes step it up if you just drive it keep it it ain't broke yet
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes