overdrive unit for my '72 suburban

[sk6strng]

Hi folks.
Love my truck but think it would be even cooler with an overdrive unit.
She turns around 3600 RPM at 70 MPH with the stock 373 gear in the rear axle, is loud on the highway and gets terrible gas mileage.
(This would also let me run a 1-piece driveshaft which would be cleaner and quieter.)
There was a 'Gear Vendors' unit sold elsewhere on this forum, but I have also heard that these may not be as duable as other units.


I would love to discuss ideas and recommendations for this with the experts on this forum.

Thanks all and have a great day!

[capev86]

ummm....you shouldn't be turning quite that fast with a 3.73 my 72 burb with 4.57 rear turns about 3200 at 60. partly the reason you are getting lousy gas mileage is you are driving too fast. you are moving a lot of weight and pushing a TON of air out of the way. when you get the overdrive in, keep the speed at 60 or below on long highway jaunts and you will see far better gas mileage. my dad could get 18mpg out of his 84 burb with 350, 700r4 and 3.73 gears by staying away from the lead foot lifestyle. saving time does not save gas...especially in a truck. oh...and my dad had a 72 burb (1/2 ton 2wd auto 3.73) back in the 80's and he could get 14mpg with it without an overdrive!

best bang for the buck if you have an automatic is to swap in a known good used 200-4r. it is largely a bolt in deal. also run a lockup converter.....eliminate any rpm waste you can!

[ksbeatty]

I have a gears vendor in my 1988 Minnie Winnie Motorhome and have never had an issue. I am getting ready to place one in my Dodge Diesel. As you can tell I am a true believer. I have no issues with their product/

[burbguy]

the 700r4 conversion is my favorite choice, and with the 3.73's that is the optimun ratio to match up with the overdrive. I'm up in the bay area, and mike over at "keith's transmission" in castro valley is a wizard, and it was very affordable ($1,700 cash price)... just my 2 cents worth...

[IAFF2407]

if your pulling a trailer stay away from the 700R4. I have a GV and have never had a problem.

[Burb]

Just dropped a Monster Transmission 700R4 Heavy Duty rated for up to 650hp, with a lock up converter switch in to my '71 3/4 ton Suburban running 3.73 gears with Posi in a 14 bolt. **AWESOME FEEL** Will bark tires in 2nd gear.

I have the lock up switch for any future haulin, which I have done very little yet, but with the switch engaged my RPMs drop down to 1900 @ 65 mph, without the switch engaged it runs about 2500.

But I know what ya mean ... when I first got the Burban it had a TH400 w/ 4.56 gears on 16.5 wheels @ 32" tires .... we are talking 60 mph @ 3200 rpm praying there were no hills to climb.

[sk6strng]

Wow...the 700R-4 idea sounds kool.....Anyone know a kool tranny shop in Los Angeles who does this kind of work?

[budder71]

there is a huge amount of data/threads/etc on the Blazer/Jimmy forum
about the swap for the Blazer/Jimmy's and now I am going to ask a stupid
question.....would it be the same swap or configuration for the Suburban's
as the Blazer/Jimmy's ? what I am asking is does there information/data/suggestions
work the same for the Suburbans ?

[Burb]

Well my original swap was done long before I found this site, heck it was first done before I had a computer.

Only difference was the first 700R4 put in my burban did not have a lock up and it had 4.11 gears, but it hauled my Camaro on its trailer like a dream, had to look back there to remind myself I was towing something.

But the mods I made were simple, I trimmed the motor side edge of the stock transmission crossmember lip and pushed it back to line up with the longer tailshaft housing, mind ya this was a TH400 to a 700R4, and drilled new holes on the frame. I had to change out the yoke of course so when I had that done at a tranny shop I had them shortin it was well. The measurement will be determined on your slip shaft requirements. Lowered trucks will be different than lifted.

Than I looked at some pics in some of the hot rod catalogs and made a cheesy lil' over and under cable mount with a set screw for the throttle and TV cable at that time it was for an edelbrock ... in fact I still use it and its on a Holley now, better than store bought.

Other than that it was just a choice of stall.

[burbguy]

I have had friends have horrifying experiences with different tranny shops, that claimed to know how to do the swap, and conversion of a 700r4 into a non- computerized truck, and found that if your going to do the swap... do some checking with friends, or other board members in your area, to get a reputable shop build it for you. As for me, when I spoke with mike from Keith's transmission(which he came highly recommended by a friend) he took me step by step on what he was going to do... I know your in the L.A. area, but he's worth the phone call to check out besides what's better than a road trip driving back home with your new overdrive...LOL Maybe even give him a call for tech info, so when you look for a local shop you might already have an idea of what your in for so you don't get hosed

[Burb]

Well mine was ... hold your breath ... ordered online from "MONSTER" Transmissions

"Eat My Shift.com"

It has a 3 year warranty and they have a great conversion kit, includes everything but the time and labor ... cooler, cables, new yoke, lock up wire harness, flywheel cover and a converter spec'd to your engine and use not to mention it comes with auto/man valve body which works fantastic with my B&M Mega shifter.

I like a tranny that can smoke the tires of a daily driven 5000 lbs suburban with a 2300 stall.

[Longhorn Man]

I'm curiouse as to where the comment;

Originally Posted by sk6strng

There was a 'Gear Vendors' unit sold elsewhere on this forum, but I have also heard that these may not be as duable as other units.

came from. It is stronger than anything else out there... esp stock for stock. If you have the coin, a GV bolted to a TH400 would be more versatile and stronger.
If you do go the 700 R4 or 200 4R route, pay special attention to the TV cable setup. 9 times out of ten, if you just make a bracket, or try to use something stock off some other engine, odds are you will fry it. Some people have gotten away with it, many have not. If it isn't dead nuts right, it will die in 10,000 - 20,000 miles, with absolutly no warning. Read as much as you can, and a great place to start is bowtie overdrives (www.bowtieoverdrives.com).

[olblue60@aol.com]

Budder 71. I have just completed this mod in my 67 panel. I would be happy to discuss options. There are two ways to approach this modification. If and when you decide, PM me and maybe I can offer some advice on the phone. I'm a two finger typer and it would take me too longto type out. Its pretty easy. I spent 1500-1600 on the total job including a nice fresh transmission!

John

[budder71]

Thanks John !!!
was your panel a 4WD ?

[olblue60@aol.com]

My panel was born a 2wd. I had a 1972 4wd suburban which the body was literally falling off so I decided to make a chassis switch and finally the overdrive conversion !
It was easier than I thoughtit would be. I'm no mechanic either, just a carpenter.

John

[junkyardjohn]

I'M 51 & HAVE BEEN A HOT RODDER, GEAR HEAD KINDA GUY ALL MY LIFE, & I'VE NEVER EVEN HEARD OF A GEAR VENDORS UNIT FAILING.EVER.. MATTER OF FACT I CALLED G.V.s TECH LINE TO ASK ABOUT THEIR WARRENTY. HE TOLD ME THAT IF IT EVER BRAKES FOR ANY REASON TO JUST SEND IT IN FOR A REPLACEMENT, AS THEY WOULD LOVE TO TEAR APART A BAD ONE TO FIND ANY WEAK LINKS. BROKEN ONES ARE LIKE UNICORNS. I'M IN.. I BOUGHT ONE FOR A T-400 FOR THE PROJECT I'M NOT WORKING ON. JOHN (IT'S RATED FOR 1000 HP RIGHT OUT OF THE BOX.)

[Longhorn Man]

i had thought hey were rated for 1000 HP but wasn't 100% sure and didn't want to misquote

[AzDon]

Originally Posted by sk6strng

Wow...the 700R-4 idea sounds kool.....Anyone know a kool tranny shop in Los Angeles who does this kind of work?

Bowtie overdrives in Hesperia,Ca...

[extremesounds13]

I know this thread is old but does the shift linkage from the factory shift linkage attach right to the 700r4?

[olblue60@aol.com]

on the 4wd install,there are two ways to do the overdrive install. It will hook up only if moved your engine forward.