I haven't seen V8 Vega swaps in years. I seem to remember that Don Hardy offered a V8 swap kit back in the day.
There was a new 74 notchback coupe in Ancaster where the owner swapped in a hopped up 327 & a Muncie 4-speed. The car was stolen in 1974 and never recovered. There was also another V8 Vega in Ancaster in that era, a '72 Hatchback with a rumored 400 small block. Don't know what happened to that one.
Attached are 2 pics that I took at our late club's show (East-Enders) back in 2008. It is a '73 Astre hatchback with a V8 swap.