Hello guys!  I recently bought a 99 Blazer to fix up and take on the trail.  I'm planning this swap, and I'm starting to realize that there is alot more to it then just the engine.  From what I can tell, I will need to also get a tuffer transmission, transfer, driveline, axles, and I'm probably missing some things.  So I'm asking for some advice, because really I don't know what is compatable.  

I would like to put a manual transmission and transfer in it that will handle a 400 horsepower engine.

I am looking at the dana 60, but I don't know if this will even fit in a small SUV like a blazer.  Will I need heavy modification?  Does someone manufacture a 60 that will slide right under my truck?


Thanks in advance for any help or ideas guys!  

You may be putting the cart in front of the horse here.  First the 4.3 is a good engine and makes good power for its size, if you have problem with power off road it is most likely from gearing not engine. Many lift vehicles and install bigger tires but have mind blocks and use 3.73 or 4.10 gears because they think it is the best gear for this and the answer is a different motor not better gears, The answer here lays in 4.56, 4.88 or 5.13 gears with big tires not a engine transplant. If you want more power still, supercharge it and together with some deep gears it well get with the program. On axles, it is called having the rear end you want to use narrowed to fit your application but before you do that, what axle you really need depends on vehicle weight and tires size. You do not need a 60 in your blazer unless you plan to run bigger than 40's or so and if not a lesser cheaper axle will do.  

Whether is it a daily driver or not, you are no saving any gas with stock gears and 38's rest assured.  I would suggest that you limit it to maybe 35 with mostly stock parts and if you use no lockers it should hold up axle wise. The biggest killer of MPG is from the lift and the tires which increase drag and HP required to make it roll. Doing this with stock gear forces engine to work harder and tranny to slip and strain more adding to MPG loss. Even with 4.56's and 35's you are still pretty tall in OD with engine turning a mere 2000 RPM in OD at 65 MPH. It will down shift frequently even with 4.56's in head winds or grades and a 4.88 would be better. With 38's and a 5.13 you will still be turning less than 2100 RPM at 65 in OD. Deeper gear will help no hurt MPG with a lift but some seem to think otherwise and continue to lug motors and complain about MPG and blame tranny when it goes south and not the big tires with stock gears. Below is a link to a online tires size/axle ratio calculator

http://www.snoman.com/HTML/axlecalc_5a.html  

This truck will also be my daily driver, I will need to keep that in mind for my gears.  I plan on running something like 38's under this truck, I think more then that may be overkill.    This truck does not have solid axle.  I found this link on the web.. it looks like this guy ran into some steering problems.  Is this what I will be looking forward to if I change over to a straight axle, and are there other options I can look at staying with the same type of axle i have, just a stronger one?

http://rides.webshots.com/photo/2417108100060067519PNSObN