As Jack Benny used to say; "Well ..........."
You are aware that the factory never put a V8 into a Chevy II up until 1965. You can spot a '65-'67 by their five lug wheels with bigger tires and brakes. There is the issue with springs and the fact that the front suspension on a Chevy II is mounted in rubber and held in place with a few hex cap screws.
But to answer your question yes there are kits with all the parts needed to install the motor; better yet there are complete replacement front clips that you bolt your sheet metal and bumpers too that allow you to install a LS-x, BBC or the proverbial SBC without any of the modifications a I am about to list.
Oil pan is different. You need a front sump pan like those as used on a Ford only it fits a SBC. This is to clear the steering linkage.
Of course change the pan and you need a different oil pump pick-up. But Chevy didn't stop there, no, they use a special one off oil pump as well. Then there is the Z-bar or cross-shaft used if you are going to use a clutch in your Chevy II It is unique to the body. Nothing unusual there most cars and trucks have a stand alone Z-bar to span the distance from frame to block. Problem is on a Chevy II they used a special block.
Speaking of special the Chevy II also has it's own private one of one bell housing. On ever other Chevy made the clutch fork comes out of the bell housing at nine-o-clock; not on a Chevy II it comes out at seven-o-clock.
The block has a raised oil filter mount to clear the cross-shaft and clutch linkage as well. The cross-shaft is mounted lower down by the oil pan rail instead of above the oil filter as on a standard Chevy small block. Not to fear they make an adapter to mount the cross-shaft. You also can use a small stubby spin on oil filter.
There are adapters and reproduced parts to allow every one who owns a Chevy II to install a SBC under the hood. I put a BBC in mine but I do not recommend that route unless you are using a gasser straight axle kit or you use the standard aftermarket Ford Pinto/Mustang II front end kit that every one now sells. The Mustang II parts are no longer available in junk yards today because every one used them up in their rods for years after they came out. A lot of advantages from the fact that they bolt or weld onto straight frame rails to the five lug hub that supports big disc front brakes. With a Mustang II front end kit there is no need for special parts and any motor will drop right in.
People are going to say keep the shock towers that get in the way and buy all of those Chevy II only parts and instead invest in some Church Bros aftermarket parts that fix almost all of the short comings of using a Chevy II economy car (those same people wouldn't consider retaining the original part in a Kaiser economy car or a Fiat 500 Topoloino (which when all added up equals the price of the kit without the disc brakes). To be fair the Topolino was a rear engine rear wheel drive car so even though it was a light weight economy car competing with the Chevy II in '62 it can not compare directly (http://www.autopaedia.com/auta/FIAT/...(02)_-BA1-.jpg
A friend of mine is trying to convince me to buy his BBC powered fiberglass replica Topolino gas class dragster as a complete car less engine (which doesn't concern me as I built his old engine, and I know now how to improve on what I did before). Which is probably why I was thinking about it above.