Well, I am building up the lude again and would like to know from the lude owners. What is the biggest turbo you can have and still use stock size radiator? I Have drag log manifold. Thanks

 

why pair up a big turbo with a log manifold ? .. in my opinion those two items contraindicate each other.
And I am sure that you will not get a definitive answer to your question .. there's just not a lot of people that did what you are asking .. most get the 1/2 size radiator when going with a big turbo.
What's holding you back from getting a 1/2 size radiator ?