TBI Swap 700r4 adaptor choices and smog question

[Kurtis]

I'm getting ready to do a TBI swap in my 85 60 and have a couple of questions on the adaptors.

It looks like downey makes a kit with the adaptor shaft seals and motor mounts. It seems like a good deal to me.

Advanced adaptors also makes a kit with everything except the motor mounts also seems like a fair price.

Is there any difference between the two?

To anyone who has used these whats your expierence/ preferance.


I'm picking up the motor tonight a 93 tbi complete. And After I get some replies i'll order an adaptor tommorrow or friday. I want to run a 700r4 behind it, I believe some of these came with 4L60es and some came with 700r4s but I could be wrong. Any advice on the transmission choices.. I like the 700r4 without any electronics personally.
I need to Pass emissions, any one from the Phoenix Arizona area attempted this and what does it take to get it through emissions?

I've gotton a couple of opinions on the wiring harness some say modify the original and some say use an aftermarket whats everyones opinion?

One last question, So if I have complete tbi350 with all accessories and ecm and possibly an aftermarket harness rebuilt 700r4 transmission adaptor and motor mounts, Fuel pump, Shifter, tcase rebuild kit, and a flange adaptor for front drive shaft. Does this Knock off my main expenses?

Thanks again for any advice.

 

[Elbert]

I think the TBI ran the 700r4 up to around 1992 or so? not sure on the exact date. I would an aftermarket harness just because they are so easy to setup and no interface with the truck system is required other than 12 volts and the sensors. My 92 K1500 had a tbi with 700r4. There are a couple of guys here who have TBI setups, I'm sure they will comment. You seem to have covered most of the items. You'll need to figure out your cooling solution, but I think you have covered the bases other than labor if you have to pay someone. Make sure and get everything under the hoos on the TBI to include wiring, ECM, air cleaner, brackets, hoses..etc.

 

[exrsa1]

700r4

Kurtis, I sent you a PM.

 

[wngrog]

Dude there is a guy GIVING away a 700r4 adapter and case in the FS section....superb price. Jump.

 

[Kurtis]

Yea I was talking with that guy when he pmed me back he said 800 plus shipping instead of the 700 he posted in the add a little confused on that one although I'm thinking about it 700 would be a good deal. , i'm kinda on the fence as to just doing the rebuild myself and putting it together for the full expierence. I would like to have an extra case though that way everything can be assembled and ready to drop when I pull the 2f

 

[Kurtis]

Thanks Elbert, I Picked up the TBI tonight and I was happy with everything. I got to see the surburban it came out of and it was clean, The owner is putting a 454 big block in it so I got the brackets the air cleaner the alternator is new the a/c compressor has been done within the lastcouple years the starter is there and all the sensors. Its got headers but I don't know if I will be able to use them. The tranny that behind it was a 4l60e but he is keeping that so I couldnt get that. I really would rather have the 700r4. I'm just a little confused on the vss sensors I see on Downeys website in what application would I need this and in which would I not?

 

[exrsa1]

Thanks Elbert, I Picked up the TBI tonight and I was happy with everything. I got to see the surburban it came out of and it was clean, The owner is putting a 454 big block in it so I got the brackets the air cleaner the alternator is new the a/c compressor has been done within the lastcouple years the starter is there and all the sensors. Its got headers but I don't know if I will be able to use them. The tranny that behind it was a 4l60e but he is keeping that so I couldnt get that. I really would rather have the 700r4. I'm just a little confused on the vss sensors I see on Downeys website in what application would I need this and in which would I not?

Kurtis, PM member DOWNEY here on MUD. He will help you out with lots of good info.

Brian

 

[Elbert]

Make sure you figure out what trans you want to run becuase your harness will have to match...ie if you run the 4l60 your wiring harness has to plug into that trans, which would be differeent or non-existent on the 700r4. Most likely your transmission will have the VSS in it, you just have to connect to it. I don't think you need an adapter like those of us who transplanted a GM V-8 with toyota 5 speed. THe ECM needs a VSS reference to control the engine correctly.

Make a call on your trans combination and then make sure your wiring harness supports that, or you are going to have some problems. Don't let anyone tell you that you can run ok without a VSS with fuel injection.

I run the old school "rams-horn" exhaust manifolds, some other guys run block hugger style headers and I think some of the exhaust manifolds off a 5.7 caprice may work. Ask around...with an automatic trans you might be able to run the stock exhaust manifolds?

Looks like you could not get the trans that came with the engine.... I would advise you to run the same trans combination that your engine initally came with...since that's what the ECM expects to see. If not then you are most likely going to require some type of custom ECM chip.

 

[Kurtis]

So with a 4l60e the vss system is incorparted in the transmission? Is this correct, it seems like if this is the case it would be the easiest with my engine. This may be a dumb question but I really don't know. Is the computer going to have a problem with different sized tires and gears? I mean is it going to be shifting at odd points or will it still do it off of rpms?

 

[lehiguy]

So with a 4l60e the vss system is incorparted in the transmission? Is this correct, it seems like if this is the case it would be the easiest with my engine. This may be a dumb question but I really don't know. Is the computer going to have a problem with different sized tires and gears? I mean is it going to be shifting at odd points or will it still do it off of rpms?

The 4L60E is the electronicly controled version of the 700R4. If I'm not mistaken, it showed up in 1995, one year prior to the appearance of TPI. If you need to run a VSS, check out JTR (Jags That Run) or Downey. I turned mine off (requires chip programing, but I was doing that anyway) so it wouldn't keep tripping the SES light.

 

[Kurtis]

I called advance adaptors and they have a a adaptor specially for the 4l60 with a sensor in the adaptor. My only question with that left is how is it going to shift with the toyota 3.70 gearing and 33s or 35s? I'm guessing it should be fine as the sensors are before the transfer case so I should be able to use the stock ecm until I modify the motor correct?

 

[lehiguy]

I called advance adaptors and they have a a adaptor specially for the 4l60 with a sensor in the adaptor. My only question with that left is how is it going to shift with the toyota 3.70 gearing and 33s or 35s? I'm guessing it should be fine as the sensors are before the transfer case so I should be able to use the stock ecm until I modify the motor correct?

If you leave it all stock to begin with, you should be fine. There are plenty of Chevys out there running 3.70s and 33" tires. In fact, I believe 3.70 was the most common gear set ratio in the TBI trucks. You can always change it later, but as a general rule, automatics are usually happy with a gear ratio about one step taller than a manual trans would run. For example, the new Tacomas come from the factory with a taller axle ratio if equiped with automatic vs. standard.

 

[ntsqd]

My Sub (TBI) has 3.73 gears and 285's (~32.5"). For normal 4WD exploring, and not extreme rock crawling, the first gear/low-range ratio works just fine. T/C ratio is a bit lower than an LC at 2.71:1 so there may be some need to offset there.

It is the highway where the gearing falls down. It's too tall to use the OD unless I'm going over 70 mph. I actually get better mileage going 72-78 mph in OD than I do going 60-65 mph in OD. Considering that this is a 4" lifted full size Suburban that's saying something!! There is enough difference to see it SOP.
The stock tire size and gearing combo equates to roughly 4.11's with a 32"-33" tall tire so that is what my 60 will be getting.