Engine Swap questions

[85MudMonster]

Hi. Okay, I want to eventually change out my worn 305 engine. And I've decided against a high power 350 swap like everyone else does. I want to stick the 5.3L Displacemant on Demand engine from the 2005+ GM trucks/SUVs. I like the power and the fuel consuption as well. What I want to know, is will the 5.3L bolt up to a 4L60E or a 4L80E, and how much will I have to modify the engine and trans mounts to make those fit. I know that the 460LE is about 1/2" to 1" longer than the TH350 I have so will I need new driveshafts as well? Also, what transfer case will work with this combo, right now I've got a NP208, which I know is a weak case, and chain driven but I like the gearing in it. That's all I can think of for now. It'd be nice having a truck with 310HP and 20MPG.

[Captkaos]

The engine will fit along with the trans.  5.3L come in front of 4L60E, and will bolt to 4L80E's.   I would get the complete running gear including the t-case from a donor.  You will need the wiring harness (complete) and ECM for DOD.  A 4L60E is the same as a 700R4(4L60) so you just have to move the crossmember back.

Check my 73-87chevytrucks.com project thread on how to get a LS motor in one of these...

[85MudMonster]

what about transmission lenght difference? Will I need a shorter dravishaft out back and a longer one up front? or do they have some play in them? I think the front one does but I'm not sure about the back one....

[Captkaos]

You will need new driveshafts if you are currently running a TH350...