Tough fit in a vette. Go with an OD trans.
Gear Vendor unit
Thread Starter
Instructor
Joined: Jul 2011
Posts: 181
Likes: 11
From: Boiling Springs
Gear Vendor unit
I'm going to be building a 450ish hp 383 and i was thinking about doing something about doing something with the tranny. however, seeing how I still have the original th400 and that it can handle a lot of hp. I figured i would just stick with it. I wanted a little better mpg because i plan on road tripping this summer around the US. so i was looking at gear vendors and i was wondering if anyone put one of these in and what they thought? are they worth the money, will the overdrive unit drop the RPMs to under 2k at 60?
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Not much of an automatic guy but the Gear Vendors OD is expensive and ver tough to fit in a Vette. I would go with a well built 200R4 or the 700R4. They fit better and can be built to handle that Hp no problem. The cost will be less than a rebuilt 400 and Gear Vendors OD and will fit much better. Look up Bow Tie overdrives. They have what you need.
Drifting
Joined: Aug 2005
Posts: 1,443
Likes: 65
From: Wauconda IL
Check the dimensions-
I don't think you can fit it in the C3 tunnel without some (or a lot of) cutting. Also, your driveshaft will be fairly short and I don't know if you'll have issues with driveshaft angles afterwards?
Gear Vendors makes a stout unit but they are VERY pricey-
You can buy a 5-speed for what those cost.
They are great in an A or B body that has plenty of room. On a C3, Not so much.
Just my .02
I don't think you can fit it in the C3 tunnel without some (or a lot of) cutting. Also, your driveshaft will be fairly short and I don't know if you'll have issues with driveshaft angles afterwards?
Gear Vendors makes a stout unit but they are VERY pricey-
You can buy a 5-speed for what those cost.
They are great in an A or B body that has plenty of room. On a C3, Not so much.
Just my .02
Instructor
Joined: Aug 2003
Posts: 167
Likes: 2
From: BLACKSBURG VA
Gear venders overdrive
I have a GVO unit behind the stock rebuilt Muncie 4 speed on my 1973 big block. GVO works great with stick shift. It is incredibly fun to drive and strong. Big block is 496 full roller that hit 635 on the dyno. The installation only required a little cutting and fiberglass over sponge. C5 seats fit fine. GVO cost was $2900 which is reasonable if you have a transmission to put it behind. I love mine and will do it again on more of my cars.
Drifting
Joined: Dec 2009
Posts: 1,349
Likes: 34
From: Porterville Ca
I have a GV in my 17000 # Motorhome. Tough as nails, 86K miles and no problems. I wouldn't put one in a Vet due to space limits. I would recommend a 5 or 6 speed trans. My 502 Motor home cruises at about 1500 rpm at 65, I get 12 MPG if I drive normal, 10 if I'm in a hurry. Even if you gain 20% MPG, it'll take a lot of miles to break even. Will you REALLY drive it that much?If you drove 10000 miles a year, and saved 20% in gas, you would save $800 a year in fuel,It would take 4 to 5 years to pay for itself if and only if you drove it that much.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
The THM-400 is 'bullet-proof' and can take a LOT of power/torque through it. But, it is a relatively inefficient transmission. For what you want to do, you would be much better off with a 200-4R transmission that is built to take the power/torque your engine will deliver. Most rebuild places can easily supply you with that. And that will also get you the overdrive and lockup functions that will provide you with a 20-25% gain in fuel efficiency on the highway. The Gear Vendor unit will cost as much as exchanging your THM-400 for a 200-4R unit; and with the 200-4R, you don't have to make changes in the trans tunnel to accomodate the GV unit's size.
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Drifting
Joined: Oct 2005
Posts: 1,528
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From: East London/SW Essex UK
I have a GVO unit behind the stock rebuilt Muncie 4 speed on my 1973 big block. GVO works great with stick shift. It is incredibly fun to drive and strong. Big block is 496 full roller that hit 635 on the dyno. The installation only required a little cutting and fiberglass over sponge. C5 seats fit fine. GVO cost was $2900 which is reasonable if you have a transmission to put it behind. I love mine and will do it again on more of my cars.
Instructor
Joined: Aug 2003
Posts: 167
Likes: 2
From: BLACKSBURG VA
Gvo
Car is currently in the shop for carb replacement,mounting emergency brake line, and battery cut off. The tach has been working intermittently so I cannot tell you what the rpm readings are. The rear end is 3:36 and would work better at 3:55 or more. GVO allows me to shift from 1st to 2nd to 2nd OD to 3rd to 3rd OD to 4th to 4th OD. Or shift normally to 4th and then into OD. The OD is .78 . Check out The GVO web site for technical info.
Melting Slicks
Joined: Aug 2012
Posts: 2,548
Likes: 379
From: Woodinville WA
Car is currently in the shop for carb replacement,mounting emergency brake line, and battery cut off. The tach has been working intermittently so I cannot tell you what the rpm readings are. The rear end is 3:36 and would work better at 3:55 or more. GVO allows me to shift from 1st to 2nd to 2nd OD to 3rd to 3rd OD to 4th to 4th OD. Or shift normally to 4th and then into OD. The OD is .78 . Check out The GVO web site for technical info.
what they said above (200 or 700r4), or, if price is no object a 6L60e would be hot ticket (they cost nearly 10k, yes, 10,000 dollars, US)
that said, I'd go with a 4L65e, and control the transmission with a computer. GM has had those transmissions at that HP level, stock, for nearly a decade.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Depending on how they are built, the 200-4R, the 700-R4, and the 4L65 are all comparable. The "E" transmissions are electronic and require a full ECM to manage it.
If you have a non-electronic engine, buying an electronic transmission seems like overkill to me. But, if nothing else, this thread shows you have plenty of choices.
If you have a non-electronic engine, buying an electronic transmission seems like overkill to me. But, if nothing else, this thread shows you have plenty of choices.
Melting Slicks
Joined: Aug 2012
Posts: 2,548
Likes: 379
From: Woodinville WA
Depending on how they are built, the 200-4R, the 700-R4, and the 4L65 are all comparable. The "E" transmissions are electronic and require a full ECM to manage it.
If you have a non-electronic engine, buying an electronic transmission seems like overkill to me. But, if nothing else, this thread shows you have plenty of choices.
If you have a non-electronic engine, buying an electronic transmission seems like overkill to me. But, if nothing else, this thread shows you have plenty of choices.
Thread Starter
Instructor
Joined: Jul 2011
Posts: 181
Likes: 11
From: Boiling Springs
So I've been thinking going the GVO unit mainly because i'm going to be doing a massive road trip around the US come this summer. I've been thinking i may just build a 383 and getting a GVO so i can save some money on gas and just so i don't strain the motor. but I've been thinking about going with the complete ls1 swop and throwing in the t56. but I'm not to sure if it is a super hard swop out. i'm thinking i might throw around 6k into it for the summer. just trying to figure out my best bet.
Race Director
Joined: Jan 2000
Posts: 12,399
Likes: 247
From: San Jose CA
painless (and others) make a stand alone controler so if you can wire a light, you can wire the controller. Electronic control helps with transmission longevity and makes the transmission quite civilized. Of course, I like knuckle dragging as well as the next guy - YMMV
Melting Slicks
Joined: May 2002
Posts: 2,717
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
Not for the trans but for my data logging,
Installing the TPS is easy, you can buy the bracket online
I got mine form Innovate when I bought the LM1,
Neal
Installing the TPS is easy, you can buy the bracket online
I got mine form Innovate when I bought the LM1,
Neal
Last edited by chevymans 77; Mar 17, 2013 at 02:06 PM.
Melting Slicks
Joined: Dec 2015
Posts: 3,181
Likes: 732
From: Texas City, TX Texas
I have a GVO unit behind the stock rebuilt Muncie 4 speed on my 1973 big block. GVO works great with stick shift. It is incredibly fun to drive and strong. Big block is 496 full roller that hit 635 on the dyno. The installation only required a little cutting and fiberglass over sponge. C5 seats fit fine. GVO cost was $2900 which is reasonable if you have a transmission to put it behind. I love mine and will do it again on more of my cars.
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
GMPP pretty sure sells a stand alone controller bet Bowtie Overdrive does also.
I would LOVE to get a 6 spd auto, only way pry me away from a manual.
Nice stall with lockup, always in the powerband. Oh yeah!
BUT at 10k good thing dreams are for free
I would LOVE to get a 6 spd auto, only way pry me away from a manual.
Nice stall with lockup, always in the powerband. Oh yeah!
BUT at 10k good thing dreams are for free
