the plan is to do an L67 swap into my monte myself. i saw the sticky at the top of this forum. how similar is it to the 05 monte ls?

 

Do you have a 3800 now? If so, you could do a top swap.

There are two main differences I can think of:
A) the wiring harness, all you should need is a 3800 monte harness from your year (not sure what other years are compatible)
B) the axles- if you already have a 4t65e, then you won't need a drivers side axle

 

the LS has the 3.4

the LT has the 3.8