I'm wanting to install a 4l65e into my car. Now first, I do have the wireharness to support it. I also have located my tq arm off the transmission. So, with that outta the way.. My understanding is that the 4l60 and 65 are the same size as the 700r4 so it will fit w/o hammering my tunnel. What about spline counts (front and rear?). Can I use my stock driveshaft? (I know ls1 will, but what about the 65?) Is the rear tranny mount the same location on the 65 as the 60? These replaced the 700r4. So I assume the shifter linkage connects the same? Or do I need to get a 4th gen shifter and cable? I have read the 4l60 has a valve body flaw. How easy is that to fix? Was that fixed in the 65? Do trucks have different gearing in them then the car/LS1's? Now, main question. I see the 4l60e supports up to 360 ftlbs tq. That is what the LS1 pushes stock. Why did GM not put the 65(380 tq) or larger behind it? Or did GM rate these transmission low? If thats the case, then a 60 may be fine. But I think my goal will be pushing the limits of either trans. So I would rather go with the 65 if it will physically bolt up w/o any modifications.

Dale, in '97 or '98 the 4l60E went to a 2 piece case which is longer that the 700r4. the 4l65e is also a 2 piece case. only the '93-'97 were one piece cases and the same length as the 700r4. so, as long as you get one from a '93-'97 one piece case, it will bolt up just like the 700r4 does. the input spline count is the same and the output spline count is the same so you wouldn't have to change the driveshaft.


i'm not sure what flaw you are referring to to be able to answer the question about the valve body.

the 4l65e had 5 pinion front and rear planets as well as a bearing type reaction hub and shell so you could build an earlier unit using these parts and still get the benefits of the 4l65e. that is what i did with the 700r4 i am currently running.

Here's a link to some trans dimensions (@ the bottom of the page). Might come in handy...

87, thanks. So I can just get a 4l60 and if/when I have it rebuilt, just tell them to build it to 65 specs?

Blue, thanks. So it appears I'm going to have to change my crossmember

yes....i am running all late model stuff in my 700r4 including the 5 pinion planets and bearing type reaction shaft.

you should not have to change your crossmember or driveshaft if you get a 4l60e that has a one piece case.

So that would be 93 to 95 model(bascically an LT1). But I am not sure my 2002 wire system will work with that?

I'm wondering how much "slop" is in this aftermarket crossmember I have. I could possibly modify it. Or what about changing tailshafts?

Its nice I can add latemodel stuff in an older case. Gives me better search choices.

The 93 was a 700R4 but called a 4L60. The 94 4L60E can not be interchanged with any other 4L60E. 95-97 4L60E's are interchangable with each other. I don't know about 98-up 4L60E's. The 95-97 would require a thirdgen shift cable and whatever that the cable connects to on the tranny. You could steal that from your 700R4. Everything else should be fine except obviously you'll need a controller or pcm to run it and the speedo gear is set up differently.

the later 4l60e went to a 6 bolt tail housing plus it is different length tail housing. like you i doubt the 2002 wire system will control the early 4l60e.

the link posted earlier by Blue says there is a late 4l60e with a removable bell that is the same length as the 700r4 but they weren't used in LS1 or vette applications. if you can get one of those and put a tail housing from a '98-'02 camaro or firebird, that might work and let you put a late 4l60e into your car to use that wire system you have.

Yea, thats what I was going to do is try and find one of them last ones listed. But the "C" dimension is off, so I will have to make my own crossmember, or see if sphon will make one (since I have a sphon tqarm).

Now I know what I need. Gotta find one and get the cash.

Went to the junkyard today. They had no trucks with trannys. They had no LS1 fbodys.

They did have 3 97'ish fbodys with 3.8's. I see the starter is on the wrong side of the motor. IIRC this is the same bolt pattern as a v8. Could I just get a new dust shield to fix the starter issue?

I'm going to go look at a 01'ish c1500 later today to look at and see what is going on.


Also, trans cooler lines. Will the ones for a 700r4 fit fine for the 60e? Or just some slight bending make them work?

no, the 3.8 will not work. the 4.3 is the only v-6 with the correct bolt pattern.

also remember, the LS1 auto is longer than the 700r4. measure the one in that c1500 before you buy it.

as far as i know, the cooler lines are the same thread for the 700r4 and the 4l60e and in the same spot so you shouldn't have to move/modify them much if any at all.