Generator has 3 prong twist lock, house is wired for a 4 prong twist lock. Is it possible to make a power cord so I can power my house during an outage.

To wire a generator into house box without a transfer switch is both illegal and dangerous. If power comes on with generator on line could possibly kill someone.

Have a qualified electrician wire it in for u.

Chuck

Also, a 3-wire receptacle is either 120v or 240v, NOT both.
A 4-prong receptacle is 120/240v, which is what you need to feed your house through a transfer switch or breaker interlock.