just about doable with PYOBP but I would avoid FCC and head straight for immigration...at a run landside you can get from T3 to T1 domestic in 10 mins...I did a kamikaze connection like that (...on two separate PNRs...but VS still interlined my baggage, and it arrived (!!)

^) a couple of weeks ago - 70 mins from touchdown to the onward flight to GLA...but it was a crazy thing to attempt and I was VERY lucky...