5 Speed swap

Depends.
If the trans came out of a 5.2 Magnum, it will fit and work (provided your 318 is drilled for a pilot bearing, or the pocket is drilled deep enough for the input shaft and use the later style roller pilot).
If it came from a 5.9, everything will bolt up, but the flywheel will be the wrong balance (5.9 external balance) and you will need to source a neutral balance flywheel.
If from a 4.7 the trans and bell will bolt up, but again you will need to source a neutral balance flywheel since the 4.7 has an 8 bolt crank flange.
If you're going to try to put this in an A body and not a truck, be aware that it's going to take a lot of firewall/trans tunnel/crossmember reworking to get it to fit- and the amount will depend on if you are using an NV2500, NV3500, NV4500, or AX15 transmission. They also all require hydraulic clutch linkage, and most of the 2000 and later transmissions also lack the proper speedometer drive. The bigger trannies also use a bigger (143 t. flywheel, 11" clutch) flywheel/bellhousing that may require even more clearancing...
The 2500 and AX15 are the only ones with gear ratios even remotely suited for a passenger car, but they're also the lightest duty of the bunch.