Here is a thread on my old '77
Look hereIf you are going stock bottom end, change the cam (no more than 220 deg @ 0.050), Performer manifold (port matched), dual exhaust with H or X pipe, free flow mufflers, you will then have a 14 sec, 240 kph C3! You can use the stock 882 heads but ifyou can pick up a set of GOOD alloys for $1000 that would be better. Either way you need to do some porting and valve unshrouding to scare yourself over 100mph! :evil
We need to know what transmission and diff you have.
I had a comp cams XE256 and was a little disappointed. Their cams seem to drop off after 4500rpm. Still a big improvement though.