I reckon it would fair very poorly indeed.
As part of my combat ready work up on the puffer jet I did a 1v1 30 mile splits over the sea against an F4. 40 minutes later I had 2 fox2s and a guns. Not saying I was special but F4 had very limited (if powerful radar) and suffered against a modern accurate RWR. To be fair the chaps I was against tried to make a fight of it. I suppose if they'd wanted to they would have blown through at M1+ as soon as they lost the picture so fair do's that they had a crack.
Against a modern jet with big missiles, big engines and big wing they wouldn't have a snowballs.