I found out today that my stock 4L60E can't take a WOT shift without TM. It is pretty cold out today (9c) so I went out and did a couple of runs, after changing the shift points up to 6100, and lowering the TM. I was seeing a timing drop of 14 degrees at the shifts before, after lowering the TM I was only seeing a drop of 3-5 degrees.



1-2 shift


bucking 2-3 shift

 

1-2 shift I could feel it slip a little, on the 2-3 shift it started surging like crazy like it was hiting the rev limiter, and I had to let off the throttle.

So I need to start thinking about a better trans. Built 4L60E or 4L80E?
I want to make her last the winter, so I put the TM back in, plus a little.

 

Id say you could do a built 65E. Unless you want an 80.

 

I was thinking of finding a cheap 4l60e core and built it myself, an 80 would be more then I need, plus extra work, cost, and would need a new torque converter. What I really want is a 6L80E , but I would need a time machine to get one of them.

 

The cost of the 80 is what made me decide on a built 60. Till I ran across a good deal on a 65E. With what I want to accomplish, I wouldnt even test the strength of the 80E.