Great point. Even when looking at a full cosworth long block there is not that much different from stock that would justify the price premium.

Someone said it in another thread but when building an engine it is prudent to spend money where it makes the biggest difference to performance or durability. Cosworth parts don't alway align with best performance to cost ratio.

I used to envy a full cosworth engine but there are not many that are used in my respected group of high power and reliable cars. Give me an AMS or IAG build any day....