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Old 03-18-2017, 08:17 PM   #1
orange72c10
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Changing drivetrain questions

I'm getting ready to change the drivetrain in my 72 long bed to a Blueprint 383 and Monster transmission with an Eaton posi. Does anyone else run this setup? I am going from the stock 350 and turbo 350. It has the 3.08 gear ratio in the back now but I have read it will be a bit sluggish cruising around. What gear ratio is everyone running or experiences have you had? I read a lot that says 3.42 or 3.73 would be a better fit...any help would be great!
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Old 03-18-2017, 09:54 PM   #2
truckster
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Re: Changing drivetrain questions

Your truck only weighs about 200 lbs. more than my Z28. The Camaro has the stock LT1, 4l60E, and a 2.72 posi rear. It will smoke the tires from a standing start.

I don't think you're going to feel sluggish with that 383. I'd drive it before you put money into the rear.
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Old 03-19-2017, 09:13 AM   #3
orange72c10
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Re: Changing drivetrain questions

Thanks for the input...I am thinking about trying it out before buying new gears to see what it's like.. I think a lot of it's personal preference for sure
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Old 03-19-2017, 09:52 AM   #4
James the III
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Re: Changing drivetrain questions

383 cubes should have no problem moving the truck out nicely with 3.08 gears..
unless you put on 30" or taller tires
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Old 03-19-2017, 11:55 AM   #5
bigmac73
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Re: Changing drivetrain questions

I have a similar setup (in my signature), with a blueprint crate, I changed my rear gears from the 3.08 to the 3.73 if you plan on doing a lot of highway driving i would keep the 3.08 and look a little higher stall converter for a quicker off the line , I noticed a big difference in highway driving before and after the rear end swap but it also has more low end get up and go
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72 C-10 Cheyenne PS/PB/Tilt/Tach/Rear slider/
385HP/420TQ Vortec 355 /TH350 2200RPM Stall
MSD Ignition/Holley 650 DP/3:73 gear Eaton Limited Slip unit / 2 1/2 exhaust glasspacks
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Old 03-19-2017, 12:07 PM   #6
orange72c10
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Re: Changing drivetrain questions

Quote:
Originally Posted by bigmac73 View Post
I have a similar setup (in my signature), with a blueprint crate, I changed my rear gears from the 3.08 to the 3.73 if you plan on doing a lot of highway driving i would keep the 3.08 and look a little higher stall converter for a quicker off the line , I noticed a big difference in highway driving before and after the rear end swap but it also has more low end get up and go
Thank you for the input..I will probably do a combination of both highway and around town. Wonder if I do change if the 3.42 would be a good choice.

My Blueprint engine will be here next week..how do you like yours??
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1964 volkswagon, dune buggy
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1978 chevy elcamino
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Old 03-19-2017, 12:08 PM   #7
orange72c10
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Re: Changing drivetrain questions

Quote:
Originally Posted by James the III View Post
383 cubes should have no problem moving the truck out nicely with 3.08 gears..
unless you put on 30" or taller tires
Thanks for the feedback..I am running a 28.5" tall tire
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Old 03-19-2017, 01:46 PM   #8
bigmac73
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Re: Changing drivetrain questions

i was always told when i was younger was a 3.55 was a good gear ,but i not know if it is available for the GM 12 BOLT
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72 C-10 Cheyenne PS/PB/Tilt/Tach/Rear slider/
385HP/420TQ Vortec 355 /TH350 2200RPM Stall
MSD Ignition/Holley 650 DP/3:73 gear Eaton Limited Slip unit / 2 1/2 exhaust glasspacks
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