there is a hole range of things you could do to get a 186 moving but first work out what you want to do with the car, id sugest get a yella terra head for it, blue motor ign, new plugs leads, extractors a good exhaust to go with, a cam to suit what you want to do with the car( a cam shop will sugest what is right for you ) as for carbys i couldnt tell you what is good of road but im sure some one here can tell you, run 98 octain fuel if you can does make a big diffrence, but hey you could also get a low comp head and slap a sc14 to the side of it and run low boost