I would not bother with making the old block into a roller motor. Take a serious look at 2 options. Buying a fresh roller motor from the mag's from 800 to 1300 OR check out the local papers or bone yards ect ect for someone selling one. I got a longblock 89 roller 302 for 250.00 and it is a STRONG motor with lots of miles left in it. Add the other parts you will need and you still will be coming in cheaper then converting if you shop around without having to pinch pennies.... Thats my advice