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#63175 07/18/2006 5:06 PM | Joined: May 2006 Posts: 5 Junior Member | | Junior Member Joined: May 2006 Posts: 5 | I have a 64 suburban with a 3-speed & O/D (O/D not working)non syncro 1st. gear. It has 3.08 posi & 350 engine.I'm trying to get better mileage for daily driver & once in a while I pull a 16' boat. When I launch the boat I have to SLIP the clutch to make it out of the river. I came across a getrag 5-speed transmission & transfer case (NP 241-C) from a 89 K-1500. My thought was to change over, leaving the burb 2-wheel drive & have the low range for launching & high range for the rest. I got the driveline (probably will have to be shortened), clutch master & slave cylinders,etc. I will have to fab a rear crossmember. My main question is does anyone have experience with this tranny & transfer case, good or bad. Would this be a good swap or a crazy thing to do, 3 local transmission shops disagree so I'm asking for your opinions. Thanks | | |
#63176 07/18/2006 5:42 PM | Joined: Sep 2003 Posts: 2,384 Shop Shark | | Shop Shark Joined: Sep 2003 Posts: 2,384 | A lower rear would help, the 3 speed OD usually used a 4.11 rear gear. An overdrive trans would also work better w/a lower gear. If it were mine, I would find a 2wd Getrag(no transfer case) & go w/3.73 rear gears. Only bad thing about the Getrag is the electric speedo connection. brian | | |
#63177 07/18/2006 7:24 PM | Joined: Jun 2003 Posts: 156 Shop Shark | | Shop Shark Joined: Jun 2003 Posts: 156 | With the 3.08 & 350 engine, I would think You might like a 350-400 auto?
"All right, they're on our left, they're on our right, they're in front of
us, they're behind us...they can't get away this time"
Lt Gen. Lewis B."Chesty" Puller, USMC
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#63178 07/20/2006 6:10 PM | Joined: Oct 2001 Posts: 3,458 Extreme Gabster | | Extreme Gabster Joined: Oct 2001 Posts: 3,458 | I sent you a private message. I am interested in your OD if you don't want it anymore.
I have an SM420 4 speed out of a 62 Suburban if you want that, it has about a 7:1 granny gear. You probably wouldn't have to change the drive shaft.
Low ranges and granny gears are nice even with 2wd.
Paint & Body Shop moderator
A lone amateur built the Ark. A large group of professionals built the Titanic. | | |
#63179 07/20/2006 6:29 PM | Joined: Sep 2003 Posts: 2,384 Shop Shark | | Shop Shark Joined: Sep 2003 Posts: 2,384 | A granny low 4 speed & 350 will about pull ANY boat,,brian | | |
#63180 07/21/2006 1:12 AM | Joined: May 2006 Posts: 8,351 'Bolter | | 'Bolter Joined: May 2006 Posts: 8,351 | Those Getrags have an integral bellhousing, you'ld have to make a crossmember mount for the rear to use it.
Bill Burmeister
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#63181 07/21/2006 1:40 AM | Joined: Jul 2006 Posts: 49 Member | | Member Joined: Jul 2006 Posts: 49 | i bet one of those trans shops could fix that overdrive.its probably an electrical problem.
64 c10
89 rs
62 econoline
50 ford coupe
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#63182 07/21/2006 1:50 AM | Joined: May 2006 Posts: 8,351 'Bolter | | 'Bolter Joined: May 2006 Posts: 8,351 | You know, now that i think about it, there was a company called Overdrive Inc. that made a conversion for the solenoid. It was basicly a cable with an actuating lever on the tranny end that replaced the electricals. It allows the o/d to be used as a gear splitter. Unfortunatly, I don't have a web address for them, their adress was listed in the original printing of "How To Restore Your Chevrolet Truck" as P.O. Box 173, Portage, OH 43451. I'm not sure if they are still in business though.
Bill Burmeister
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#63183 07/21/2006 2:40 AM | Joined: Dec 2004 Posts: 1,897 Shop Shark | | Shop Shark Joined: Dec 2004 Posts: 1,897 | take a look at a nv5400. it is a 5 speed tranny that replaced the getrag. Available in 2wd and 4wd configrations. either 6.3, or 5.6 first gear ratios, and an overdrive of .73. 3.08 are already pretty good freeway gears. I'm not sure if a 350 could push your truck in overdrive as it would turn your 3.08 into 2.25 rear. 65mph at around 1750 rpms with 28 inch tall tires. might be hard to climb hills.
the first gear ratio is much lower than that of any 3 speed. the nv4500 is built to take the power and load. | | |
#63184 07/23/2006 4:14 AM | Joined: Mar 2005 Posts: 637 Shop Shark | | Shop Shark Joined: Mar 2005 Posts: 637 | I have a 5 speed in my 1/2 ton GMC with .73 od 5th gear and put in 3.08's in the diff. 350 engine pulls 5th just fine except when towing my car trailer with a stovebolt on board (only when it's broken). My mileage went up about 2 m.p.g. when I changed from 3.42's and driveability was the same. | | |
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