Whether or not it's an easy install depends on what it's going in. If it's a 73 & up Chevy p/u it's a simple bolt-in, save for driveshaft shortening or lengthening. A little more work for 67-72 pickups; even more for the 63-66s. And for stovebolt engine pickups (62 & before) extensive mods have to be made (usually entire driveline swapover plus custom floor pan mods.

I'd thought about going with the 700r4 in my 66 stepside. Since my truck came with the later 6 bellhousing (which is the same pattern as the small block v8) a 700r4 will bolt in directly. Only changes would be moving the engine forward to give room for the trans bellhousing to clear the low floor. I'd also have to fabricate a trans crossmember or find one from a late 70s-early 80s Suburban.

So the amount of work depends on the year vehicle you have and it's current drivetrain. The older and more original the more work there'll be. Hope this helps.

-wftyler