Turbo 350 for 700r4 swap

[MASTERBrian]

As the title says, I have a turbo 350, I believe it's the long shaft haven't measured it yet, I'm my '60 suburban. Truck sat for fifteen years do I want it at the least gone through as motor it's frozen solid. Quote is about $600 around here and that is with shift kit and reworked stock converter. A friend of mine picked up a couple of 700r4's from tranny shop that was closing doors. He believes they are '91's and he'd sell me one for $400.

Now the debate, do I swap or not? I know the 700r4 offers several benefits like 4th and lower gears, but I don't want to spend a fortune for this conversion.

I know it needs something to 'lock it in', probably shorten driveshaft and then a kick down to carb. I also realize I need to move mount back about 4".

$$$ wise what am I looking at as well as time? I don't mind some extra work, but I'm not sure about $1000 on top of the tranny price. My column is a three speed column I believe, but I was told either I lose low 1 or park. Someone else said I can just adjust the linkage to give it a longer throw.

Let the info begin....

[The Rocknrod]

Here is some info on cross members and what you need and might be able to use. Not sure if you have the X-frame:
http://www.persh.org/pickup/700R4.htm

[Clyde65]

Bow tie overdrives has your TV cable and brackets.

I would also suggest your reach out to Clinebarger here on this forum, he is the GM automatic boss, he has a couple write ups for building a 7004r if it needs that( which it might, it is 26 years old!)

Good luck!

[MASTERBrian]

My understanding on the tranny is that it was/is a rebuilt stock unit that was sitting on shelf waiting for a customer that needed one. So it shouldn't need a rebuild. Just whatever I need to install into my truck.

[Captainfab]

You will have to fabricate a new trans crossmember or modify your existing one. With the 700R4 you must be sure to properly setup and adjust the TV cable. Otherwise you will burn up that new trans in a short time. You need to get those components from Bowtie Overdrives as Clyde65 said. You will also want to search the Engine and Drivetrain section for the proper procedure to adjust the TV cable to achieve the correct line pressures in the trans. Member Clinebarger is our forum trans expert.

[Clyde65]

Originally Posted by MASTERBrian

My understanding on the tranny is that it was/is a rebuilt stock unit that was sitting on shelf waiting for a customer that needed one. So it shouldn't need a rebuild. Just whatever I need to install into my truck.

How long was it in the shelf? I would open it up and inspect it or have a reputable trans shop perform an inspection, wouldn't be much I would think. It might save you grief because if you put the trans in and end up having to remove it, your burb is down longer and your po'd.

Good luck!

[MASTERBrian]

Originally Posted by Clyde65

How long was it in the shelf? I would open it up and inspect it or have a reputable trans shop perform an inspection, wouldn't be much I would think. It might save you grief because if you put the trans in and end up having to remove it, your burb is down longer and your po'd.

Good luck!

I wondered that question as well. Though I'd love to have a 700r4 to gain that 4th gear, in case it ever became important, I'm not sure it's the right thing at this time as I am trying to stick with a budget on time & $$$. The problem is I keep getting people saying go 700r4 or you'll regret it....maybe I will, but I'll also regret spending another grand and having to hold off on getting her on the road another 6 months or something. IF I can pick this up for a reasonable $$ amount, all is good inside and installing isn't too bad, then I feel silly not going that route.

[Clyde65]

Here is what I would do in your shoes.

I would ask the person who is selling the trans if they would be ok with you or them sending it to abc shop for an inspection. If they say no then walk away, if they say yes, that would be a well spent $50-100.

We have all been where you are, tight budget but also a big desire.
A 7004r will allow you to stay with a low rear gear, say a 3.73:1 or lower and still be drivable on the highway.

If you don't drive highway then walk away now. If you do, then you have a reasonable option and a plan.

If you have a high rear, say a 3.08:1, it will still help but not as much as the lower rear gear.

Now you have the full skinny imo, good luck with whatever you choose.

[MASTERBrian]

I'm thinking about doing that as well. Might go talk to a tranny shop in morning to discuss with them as well.

I am told it's just moving the cross member 4" back, but likely a shortened driveshaft. I think I have a long shaft T350, if not it's a mid shaft, I need to put a tape measure to it, just haven't yet. Either way I think the 700r4 is about 1-2" longer than the long shaft T350, if what I read was accurate.

As for the rest am I'm guessing the tranny shop will set me straight. I think I have a 3.90 rear end, if not it's a 4.11, so I'm definitely very low.

Thanks!

[SS317]

I installed a 700R4 in mine and I love it. I had to shorten the drive shaft a little, took it to a shop and it cost me around 75 bucks. Installed new transmission cross member, bought it on ebay and it worked great. Ebay was cheaper than even having someone fab it up. And I had a tranny shop do the TV cable just for my own mental security. I also had a pressure switch installed for locking up the torque converter and it works great.

So much nicer to cruise in the truck now and I can actually talk to the passenger instead of yelling. I'm all for the 700R4 if you can figure out how to swing it.

[Clyde65]

One thing to look at, how is your parking brake done? My 65 was on the trans mount so I had to swap that out to the 66 which isn't anywhere near the trans mount.

[MASTERBrian]

Being that this is 1991, I guess I have to either install a computer of sorts of put a switch in to lock it in. That doesn't sound like much fun, I think there might be another solution, but I'm not really sure.

Two of the tranny people I spoke with seem to say this year doesn't make a good swap....Hmmm. as for opening it up, the one I spoke with today said if he opens it he wants to rebuild it.

As much as I'd like to go with the 700r4, I'm not convinced this is the right opportunity, but until I get the motor and tranny pulled I'm going to keep looking into it.

[verdell]

Originally Posted by MASTERBrian

Being that this is 1991, I guess I have to either install a computer of sorts of put a switch in to lock it in. That doesn't sound like much fun, I think there might be another solution, but I'm not really sure.

Two of the tranny people I spoke with seem to say this year doesn't make a good swap....Hmmm. as for opening it up, the one I spoke with today said if he opens it he wants to rebuild it.

As much as I'd like to go with the 700r4, I'm not convinced this is the right opportunity, but until I get the motor and tranny pulled I'm going to keep looking into it.

I can certainly relate to building on a budget but keep in mind, a 1991 700r4 doesn't require a computer, just a kit to lock the converter which can be done automatically. When properly built and dialed in, they do really well. Hope you can start enjoying your truck..

[MASTERBrian]

Originally Posted by verdell

I can certainly relate to building on a budget but keep in mind, a 1991 700r4 doesn't require a computer, just a kit to lock the converter which can be done automatically. When properly built and dialed in, they do really well. Hope you can start enjoying your truck..

Then the tranny guy I just visited with it's out. I have a few others to visit in person with. He made it sound like anything after 1987? Needed a computer or a switch on the dash.