Very good article on this.
Includes story of change from Climax 4 to Repco V8 power, and some fantastic photos.

https://primotipo.com/2016/02/12/jim...gans-lotus-39/

Interesting as mentioned in article that this car and Brabham's BT19 were developed for the same purpose, to take the stillborn Climax Flat 16.

Thoroughly recommended.