[mongocanfly]

I felt the same way when I did my 1st one...but I was amazed at how everything just fell in place..I did it before I had this site to help, so my guidance mostly came from a speedshop..
1st thing on your list is the biggest..make sure you get a good running and working setup..
1750 is a decent price for a complete setup....zip codes greatly affect prices..
If you can hear it run , just look for smoke, listen for odd noises, put a code reader on it...
120k on a LS isnt bad..
That's not much of a warranty considering your gonna eat most of that up with the install..
There are quite a few that have done the 68-72s so they can offer better advice..
On mine I used the ol Ebay adapters for motor mounts....lots use the DD so they must be pretty good
Your stock radiator is plenty for the engine, you'll just have to plumb it up..
Decide if you want elec fan or mech
If you get a dbw engine ,make sure you get the pedal and module
Make sure you get the ecm
Theres gonna be some hurdles to cross with the install..not sure about the trans xmember..
Driveshaft may need some work
shifter linkage connecting
On the fuel system you'll need to go high pressure..its been done on incab, but I'd get rid of the incab tank, if that's what you have..
you'll need all high pressure fuel lines..depending on the engine it could be a return rail or returnless rail..cross that bridge when you get to it..
On the exhaust...it depends if you want manifolds or headers...either way you'll have a trip to the muffler shop.
I hate wiring , so I always have bought my harnesses...its nice to just plug it in and go..
I also have used psi, but my next one will be a BP harness..
The BP has a longer main harness allowing the ecm to be mounted under the seat..
Another hurdle is do you have a shop to work out of..
Another set of hands is nice to have also...but I've done all mine by myself..
You'll need a engine hoist and a good basic tool set