I recently flew to Atlanta to look at a Contemporary with a supposed 427 side oiler in the car. It was in fact a side oiler, but had no casting numbers or ribs.
To the original poster, remember that "the engine has been broken in" only means its been started and run, checked over, then run through a few dyno pulls for some tuning. That's maybe the equivalent of half a dozen red light starts and 2-3 miles down the street and back. So its still very new, very tight and needs to be treated with care and respect for the first few hundred miles. I'd change the
oil again at 100 miles, to be double sure you got all the micro debris from machining and assembly. Use only the best 93 octane fuel and watch your temp and
oil pressure gauges. Let it get the
oil temps up to 80C or above before leaning on it and don't get in a hurry to start over-revving it.
Jim