So the question is 700r4 or 4l60e? Stock 76 stock rear gear, 3.08?

 

Im currently going with the third option... The bolt in, 2004r. But the two choices your considering make more sense with the 3.08 gears.
You may or may not know, the 700r4 uses a TV cable to control its shiftpoints. the 4l60E is electronic.
If your comfortable with installing a computer to control the 4l60e then Ive read it has more potential for adjusting shiftpoints and such. I guess it makes more sense if you already have EFI as well..

 

augiedoggy is correct and there are a few manufacturers that make controllers for the 4L60E. I went with the HGM controller. Great product and great customer service if you have any questions. I did do some additional mods to the 4L60E. when I had it built I also added a Sonnex 1-2 gear change. It actually makes the 1-2 gears very similar to the 2004R. It gives you the gearing of the 2004R but the controllability of shift points and pressures of the 4L60E. I am also running 3.73 gears and a Edelbrock Pro Flo 4 system which communicates with the HGM controller.
My biggest complaint with the 700R4 and the 4L60E is the huge gear jump from 1st to 2nd. That and the heavy duty input carrier is why I did the Sonnex 1-2 kit. The Sonnex gives a 1-2 ratio of 2.84 1st and a 1.55 2nd gear.

200r4 2.74 1.57 1.00 0.67 2.07
700r4 3.06 1.62 1.00 0.70 2.29
4L60E 3.06 1.62 1.00 0.70 2.29

 

I put a 4L60E in my '73 last summer with the stock 3.08 rear. Love the combination. Can spin the tires off the line and the engine cruises at 2000 - 2100 RPMs on Texas highways. Sourced the tranny from Silver Sport Transmissions. It came with everything needed including fluid, driveshaft, controller, shifter conversion kit, etc. The 4L60E also gives you the option to install paddle shifters (a kit for our cars was available when I first researched this a couple of years ago).

DC

 

I have been searching for a kit that would work on our tilt/telescopic wheel but still haven't found one yet. I did talk to HGM about one but it would probably lose the telescopic function. I still want to look more into it and see if I can modify a paddle shifter setup that would work with both functions.

 

If I remember right, HGM offered two mountings options, one for a regular splined GM shaft and a universal option that required some type of adapter from Grant. I did not explore whether or not the tilt/tele function would be compromised. That might be a deal killer for me although I really don't use either feature much since I'm the only one who drives my '73.

DC

 

4L60e will give you so much more control over the shift points. You can change the curves to get it to shift at every throttle and speed right when you want it to shift. Paddle shifters are an interesting idea, but I would say that you won't find you need them with the right tune because the transmission will simply respond to your foot on the gas and be in the gear you want with no need to manually force it into a certain gear.

I like the idea of the 1-2 gear change, but it's way too much money for the change you get. It lowers the ratio of both gears so the step between 1st and 2nd gears really doesn't change very much. The ratio difference 1st gear to 2nd gear is 1.89 with the stock gears and 1.83 with the new gear set. 200-4R 1/2 ratio change is 1.75. So, the numbers seem to suggest the new gear set makes the 1-2 change like a 200-4R, but the step didn't get much better than the stock step.

 

I think the issue is that the adapter for the paddle shifter does not have the notched area for the telescopic lever. You might be able to modify it to make it work but I wasn't willing to risk the expense just to try. LOL.

 

You are correct, it is an expensive upgrade but it is also a 6 pinion carrier vs. a four or five pinion carrier. Supposedly better on that point. The new gearing just makes it a little more of a close ratio trans vs. a little more of a wide ratio trans when compared to the stock gear set.

 

It's that "e" part that is the sticking point with this conversion. If you go with an electronic transmission, you need to research it and be certain you know what it takes to install it properly.

 

Exactly. One big point is that it requires a controller vs. a tv cable to control the shifts.

 

FYI: (In case there is a budget )
The "e" conversion will cost an extra $600+ more than the 700R4 .

The capital "E" (bells/whistles) will cost an extra $800-$1,000 more than the 700R4 .

 

I ve had several 700R4s and liked them quite a bit. If you going stay stock motor and gears I would go with the 700R4.

 

Agree much about the control over the shift points. The Silver Sport kit also comes with an A/B switch so you can easily switch between two shift programs. My A program is a general cruising around shift setup. My B program is for more aggressive driving and makes it seem like you've installed a shift kit.

I'm not sure what the big deal is about the gap between 1st and 2nd gear on these transmissions. I've not found it to be an issue at all. It's the same transmission in my '05 Suburban and I don't have any issue with the 1-2 shift there either.

DC

 

Maybe because enough "experts" have told people it's a problem? I don't have a problem with it. Cruising I see maybe 400rpm drop shifting 1-2.

I've set a few up with the bottom part of the curve for low %TPS shifting in the 0-25% range at fairly low rpms then ramp up to probably 80% of WOT by about 60% TPS. That way, with light throttle it granny shifts but as soon as I get into the pedal it gets sporty. I also keep the up and down curves close so it'll down shift quickly. If I'm cruising and roll into the throttle I get TCC unlock, 4-3 then 3-2 all happen sequentially before WOT. GM stock loves to put the upshift curves so high that once an upshift happens it needs a LOT of throttle to get a downshift again, and I hate that. You roll into a stock GM and nothing happens till your foot is most of the way to the floor then it dumps pretty much right from 4 to 2.

 

I don't think it is necessarily the cruise rpm shift drops between 1-2 that is the issue but more so the wide open throttle rpm drops, that is where the difference is. It is like comparing a close ratio trans to a wide ratio trans. Either one works just fine but there are fans on both sides of the fence when talking close and wide ratio transmissions. Also is dependent on how the car is set up.

 

I wanted to avoid the E factor so I used a 700R4 with a TV cable... works great and makes the car much more user friendly.

mardyn

 

I put a 700r4 into my '72 with 3.08 rear back in 2015.

all the people here were telling me to go with the 200-4r, easier, cheaper, no tail shaft mods etc.... but they are not available down here, and cost to import/rebuild would have been stupid prices.

after all the trouble I had getting the 700r4 fitted and adjusted I would defiantly go electronic controller, full adjustability for pressures and shift points.

I have another diff at home to build up and swap over with 3.36 gears.

 

Thanks for all the responses. I'm gonna go with the Silver sport route. 4l80e Its a complete kit. Think all ill need to do is cut the shaft. And of course install it. I like that everything will be there in a complete kit.

 

I just installed one of their 4L60e's in my 80 L82. I'm still in process of testing it out as I had some new engine noise to deal with soon after completing the install.

The SST folks are very accessible and do work quickly to help resolve issues. For example, the crossmember arrived with the parking brake bracket bent. They sent a new one immediately. They also worked with their vendors to resolve any issues which came up.

Some things that might help you to plan if you do go with them.

The cross member - very well built, but provides less clearance for exhaust than the original crossmember. Still, a 2.5" exhaust can be be kept above the bottom of of the tranny pan. Big issue with the crossmember is the change in the tranny mounting bracket. Likely not an issue for most, but if you plan to use the stock cat based exhaust on a 75 to 82 you'll need a new plan. It interferes with the front Y-pipe.

Cooling lines - they provide 6' long braided hoses instead of purpose built steel tubes. The length forces them to go in pointing back first before looping 180 deg to the front. This runs them over the the exhaust and very close, about an inch separation. Some wrap will be necessary. Note, DC3 managed to run his along the engine. Alternative would be to get a set of 82 cooling lines and that used the 700R4 so I am guessing those lines will work on the 4L60e.

Tranny mods -

• SST does use later model 4L60e's which had most of the bugs worked out. The trans upgrades in the stage 1 are pretty limited to just a better frictions package. But the supplier does dyno test all the tranny's after the build so they ought to be in decent shape.
• The tail unit is modified to be able to mount a mechanical speedometer cable output. It is not necessary to use a module which reads the digital speedometer pulses to drive a motor to drive a cable or to convert to an electronic speedometer.

Shifter kit supplied will cause you to destroy your existing shifter housing to put in the new detent bracket. If you don't want to destroy this you might just get a housing made for an 82. Also, the new gear position marker simply glues on top of the old and is non removable. It is solid black background to hide the old marks but that blocks the view of the shift pointer. In my opinion it makes it unusable to be certain where the shifter is pointing. Again, better to get a unit made for an 82.

Placement of the TCU. No guidance from either either SST or HGM on this. I opted for putting it behind the drivers side kick panel. OK in an 80 as the vent which was there in the early vettes is gone, so there's room. DC3 put his in the engine compartment in a custom built housing I believe. Others found space up in the dash.

TCU cable placement - Since my TCU was in the the cabin I punched a hole for the through the top of tranny tunnel offset to the passengers side. There was plenty of cable to reach there from the drivers side placement of the TCU. I punched a hole above the pedals to run the TPS cable to the carb.

Throttle position sensor install - Took some work to mount on the Q-jet. On the 80 had to cut out a section of the throttle cable bracket to provide space for the sensor. This definitely reduced the stiffness of the bracket. Also, had to drill out the boss the the throttle cable attached to on the carb throttle plate to put in the part that works with TPS linkage. Lastly, had to put some spacers in their linkage to get good alignment. I have a thread on this issue but too lazy to find it tonight.

Dipstick tube - very difficult to install. DC got his in. I gave up as the clock was ticking on the transmission warranty which starts the day the tranny is shipped. I opted to put a Lokar flexible tube in.

So far, what little testing I've done, I like the unit. It is great to have the ability to see the temperature and line pressures, etc. when cranking up a new tranny and be confident it is working OK.