Thanks guys.
I asked them earlier today about running a 3" up the 4" and using the 4" as a sleeve. He shot that down too and said the sleeve had to be 2 sizes larger then the pipe.
I'm trying to figure the best way to cut the concrete where it is 7-8" thick. Most saws I can rent will only go around 5". I will probably need to do multiple passes if possible.
What do you all think of this plan?
Strike a line about 1" on the outside of the 4" pipe.
Get a 12" long masonry bit and drill holes every 4-6" about 8" deep.
Take the concrete saw and run it down the line.
Start swinging away with a BFH.