I am going crazy on a new 408 stroker that should put out over 750hp. My 03 Denali 4L65 is not going to hold up even with a super build. Has anyone sucessfully swapped out an Allison or the 6L90 or even 6L80?

 

put in a built 4L80E. problem solved.

 

but to answer the question, no, no one that i know of has swapped in a allison trans, you would need a 2" bodylift minimum to fit it anyways. only one person that i know of has swapped in a 6L80e, and he swapped in a whole L92, 6L80e, AWD setup at one time. i think speartech swapped in a 6L80e in a truck but not sure

im 95% sure no one has swapped in a 6L90e yet either

the 80e if built will hold over 1000rwhp/tq