XP Falcon ute

This was origionally my Dads and I helped him build it but I liked it so much I had to buy it off of him. The origional running gear, 6 cyl engine and 3 speed manual worked fine so we left it as was. This is how I drove it for ages untill one day travelling on the Great Eastern Highway Bypass Road sitting on 100kph(the speed limit)without any warning lights, rattles, etc.there is a huge explosion and the ute is fishtailing badly across two lanes of traffic, so I go for the brake and clutch and both pedals hit the floor with no resistence. I then head for the median strip and bog it to stop the thing. What happened? It seems number 6 went outside one side of the block,went back inside then went outside the other side of the block, then shredded the sump, then smashed the starter motor off the bellhousing (shattering that in the process). The starter motor went flying as far as the cable would allow it then it flicked back smashing the brake and clutch master cylinders of the firewall. What to do next? Well you've got to change all of this to put a V8and C4 auto in it, so thats what happened along with disc brakes on the front.