building a mild Daily driver 318

Yes and no.
Yes with a few upgrades, and
No cuz it won't bolt up to the engine. They have different patterns

For 300hp, the 904 would be,IMO,better.

The 69 Valve body, and the bands and the small slanty clutch-packs wouldn't be optimum tho. Better is a 73up teener 904, with the Part-Throttle KD valve, on the VB.