Overdrive vs Tranny with overdrive????

[87Bob]

Anyone out there who may have had both? Which is better? I have a long term project 85 long box. I am trying to decide if I want a 700R4 or a overdrive unit like a Gear Vendors. It has a Turbo 350 in it now. Also I saw some where someone had said something about a 1 ton came from the factory with one is that true? If so was it behind an auto trans and what year was it? Thanks!

[andrewmp6]

Gear Vendors cost more then a simple tranny swap.And you'll have to make a cross member to hold it and shorten your drive shaft.If you tow with it you have to put the unit in neutral down hill or you'll burn it up.

[87Bob]

Originally Posted by andrewmp6

Gear Vendors cost more then a simple tranny swap.And you'll have to make a cross member to hold it and shorten your drive shaft.If you tow with it you have to put the unit in neutral down hill or you'll burn it up.

I understand about the cost. My thought on that was that the old 350 was stronger than the 700R4 was why I thought it might be better. I don't understand about the "you have to put the unit in neutral down hill or you'll burn it up". I would expect it to act like a Jake Brake if left in low and in high it would be more free wheeling. Could you explain? (Without your explanition) Would I be better to look for a auto trans out of a C20. I figure to pull a enclosed car trailer when loaded would max out at about 8,000 lbs..

[silvereagle07]

The older 700r4's were junk. The would overheat when towing alot. The aftermarket is full of built overdrives that may fit your needs. You could also look a 4l60s or 4l80 if you are going to tow alot. I think the Gearvendors is used more in cruising. JMO

[Wild83C10]

You could easily build a 700R4 or a 200R4 to take just about whatever you can throw at it. The 700R4 has a steep first gear and big drop in gear size from first to second. Which makes it difficult to use for drag racing.

The one advantage to the gear vendor overdrive unit is you get more gearing options, so you would have like a 6 speed, I believe.

[andrewmp6]

My friend has a diesel dodge ram he tows a top fuel car in a big 5th wheel trailer with.He burned up his Gear Vendors unit and there answer was he should have put it in neutral down hill.They did try not to replace it but they did in the end.But as mad as they made him he sold the unit they sent him.Its more like a semis 2nd gear box gives you a low a high and a neutral gears.And you have a controller to it and you have to shift it yourself .Yes a stock 700r4 is junk but build it up they are ok.8000lbs would be fine as long as the truck can take it and good trailer brakes.

[68c10owner]

You could always go with the 4L80E. You`ll need a control box but thats probably the strongest "stock" OD tranny. It`s basicaly a th400 with a od gear. My buddy kept going threw th400`s and 700R4`s in his chevele with a blown 454. He put the 4L80E in and it has lasted alot longer. He did break it not too long ago but I can`t remember what he broke but we`re talking a mid 10 secong street car.