4L60 limitations

[ShielatheC10]

Hey y’all

I have an 86 C10 that I am swapping a 5.3 into. Originally I was going to run the stock 700r4 (for cost reasons) until many people on here told me that was not the best route. So I have decided to go out and find a used 4L60. My questions are these:
1:What should I look for in a used 4L60?
2:What are the limitations of a stocker as I am hoping to make 400 HP/400 ft lbs (The truck will be a daily driver)
3: Lastly, are there any essential upgrades to make when I do find one?(outside of getting it worked over by a professional trans guy, which I am not)

 

[GTX63]

The best years of the 700R4 are 1987-1992. I cannot speak for others but I will speak for myself and the guy who has been rebuilding transmissions for me for a number of years. The later model 700 R4 are good transmissions. They are plenty strong enough for 400 HP.
That said, there are folks who will knock the 4l60. With either tranny, don't cut corners on the torque converter.

 

[HotWheelsBurban]

Most bulletproof trans is gonna be a 4L80E. But the later '60s are sturdier than the early ones. Lots of '60s available in OBS/400 Burbs and Tahoes, just go through it and be sure it's got fresh fluid and filter.

 

[RetroC10Sport]

4L60 is a 700r4. 4L60e is the electronic version.

 

[Ricko1966]

Hey y’all

I have an 86 C10 that I am swapping a 5.3 into. Originally I was going to run the stock 700r4 (for cost reasons) until many people on here told me that was not the best route. So I have decided to go out and find a used 4L60. My questions are these:
1:What should I look for in a used 4L60?
2:What are the limitations of a stocker as I am hoping to make 400 HP/400 ft lbs (The truck will be a daily driver)
3: Lastly, are there any essential upgrades to make when I do find one?(outside of getting it worked over by a professional trans guy, which I am not)

700r4 and 4l60e are the same but they got upgrades as time went on,if your running a computer on the 5.3 not a carburetor, a 4l60 will have most of the upgrades and you won't have to figure out TV geometry. If you're using a carburetor the money you would spend getting a controller and a 4l60 you can spend building your 700 TV is easy on a carburetor.

 

[Hunter79764]

If you are running EFI, run the 4L60e and have it rebuilt/upgraded to the 4L65/4L70 specs. Doing the TV cable on a 5.3 will offset any savings you might have otherwise.
If you are doing a carb (and you should only do a carb if you really want to, it will cost the same or more and generally make the swap more complicated, not less), the TV bracket is doable and you could have the 700 rebuilt by a good shop and be fine.

Either way, stuff the biggest transmission cooler you can, preferably after the radiator cooler, and keep up with the fluid/filter changes. that will do more help than just about anything else.

 

[Matt69olds]

If you are going with a 5.3, look for a 4L60E. Use the computer to control it.

I build my 4L60/4L60 with the same basic recipe. Install the upgraded dual cage input sprag, use the factory 7 clutch setup for the 3-4 clutches, use a wide 2-4 band (make sure the reverse input drum is absolutely flat) depending on application a upgraded servo is a good idea, and without a doubt some valve body work.

 

[ShielatheC10]

Thanks guys, I will be running EFI controlled by the MSD 6014 box. That’s the plan as of now, I haven’t bought the box yet.

 

[TotalyHucked]

I've got a ~425hp 5.3 in my '85 with a 4L65E behind it. Pulled the motor/trans out of an '06 Envoy Denali with 104k miles. I rebuilt the top end of the motor and slipped a healthy cam in it, the trans got a Circle D 3000 stall and a fresh filter, that's it. Been beating on it like it owed me money for 30k more miles with no issue. As stated above, if you find a cheap one, just get it built up to 4L65/70 specs from a reputable builder and it'll handle anything you throw at it. 4L80s suck, the ratios are terrible and the suck power, stay away from those.

 

[Matt69olds]

Just to clarify: a 4L65E has 6 clutches in the 3-4 clutch pack. The 4L70e has 7 clutches, planetary gears with 5 pinions instead of the usable 4, and the updated dual cage input sprag.

If you install the 5 pinion planetary gears, make sure you are buying GM stuff or qualify parts. I did a 4L60E for someone years ago that bought 5 pinion gearsets from EBay. They lasted 1000 miles. I’m not sure if it was lousy heat treat on the gears or shafts, but it trashed everything. Tore it down, cleaned everything up, reassembled with the factory gears and as far as I know it’s still going.

The 4L80 gear ratio is identical to the old 400 trans for the first 3 gears. The first gear ratio of a 4L80 and 400 is 2.48, the first gear ratio of a 700 is 3.06. GM design the 700 with that low gear to help get the underpowered cars and trucks of the early 80s moving. While the first gear ratio is nice, it’s the gear ratio spread between first and 2nd gear really sucks.

The only disadvantage the 4L80 has over just about anything else is the weight. They are heavy. As for absorbing power, it MIGHT be slightly slower (you possibly would see it on a timeslip, but not feel it with your “butt-o-meter”) but the difference isn’t much.

 

[HotWheelsBurban]

Th

Just to clarify: a 4L65E has 6 clutches in the 3-4 clutch pack. The 4L70e has 7 clutches, planetary gears with 5 pinions instead of the usable 4, and the updated dual cage input sprag.

If you install the 5 pinion planetary gears, make sure you are buying GM stuff or qualify parts. I did a 4L60E for someone years ago that bought 5 pinion gearsets from EBay. They lasted 1000 miles. I’m not sure if it was lousy heat treat on the gears or shafts, but it trashed everything. Tore it down, cleaned everything up, reassembled with the factory gears and as far as I know it’s still going.

The 4L80 gear ratio is identical to the old 400 trans for the first 3 gears. The first gear ratio of a 4L80 and 400 is 2.48, the first gear ratio of a 700 is 3.06. GM design the 700 with that low gear to help get the underpowered cars and trucks of the early 80s moving. While the first gear ratio is nice, it’s the gear ratio spread between first and 2nd gear really sucks.

The only disadvantage the 4L80 has over just about anything else is the weight. They are heavy. As for absorbing power, it MIGHT be slightly slower (you possibly would see it on a timeslip, but not feel it with your “butt-o-meter”) but the difference isn’t much.

The '80 is a stouter truck transmission, that's why they put them behind big blocks and in the 2500/3500 trucks. They're more tolerant of towing in overdrive; not a good idea to do that with a '60.