After my 'normal' 1600 T1 died due to ingress I looked at several options and taking into account power to weight ratio etc and what I expected to be doing on a daily basis I decided 100 BHP was enough without sacrificing reliability but that came at a price of over 2,000€ on internals plus upgrading the DRLA 36 to 44s and a LOT of physical effort (and a dead Dremal) porting the new big valve 044 heads.
So as a 1641cc A&A kit was the largest without engineering needed I went for that, but also worked out that to get near the 100BHP I would need to 'upgrade' the internals for performance stuff in order to stay well with the reliability band at higher RPM..
One thing led to another but I am confident I now have a bullet proof motor with high performance capabilities (If I choose to use it).
To save space I give the link to my engine page.
https://ukhozi.page.tl/Engine.htm