Brakes and suspension first and you have heaps of options for the 120y which is great.

Then you can also consider a cheap L series with a turbo, no pollution gear and suits the period of the car. Top to bottom they are more bullet proof than an L or CA. Here is just an example of why they can eat turbo porsches and commonhoe v8s.
http://ozdat.com/forum/viewtopic.php?f=62&t=32113