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Depends upon your pan choice. If you buy an aftermarket Holley LS-x into muscle car engine swap kit no, other wise yes.
The Holley kit includes motor mounts, headers oil pan and adapters to allow a manual tranny to be used if desired (you still need to buy a hydraulic clutch kit and fly wheel they just provide the shims). Chevy never put the passenger side high bolt hole in the block because if you drill and tap it for a bell housing bolt it will go through into the number eight cylinder.