Does anybody remember mobile engine overhaul outfits?

Oh yes.
Circa 1977 in a trade school tech auto class.
Guy comes with a portable engine boring machine.
Sleeves a 396 in the car.
Or I think it was on the bench.
Anyway.
When he finished first boring the cylinder he says
"This is the high tech part"
And takes a piece of wood and a hammer and pounds the sleeve into the block.
Then proceeds to bore it to size.
Had a shop vac I think to suck the chips.