I have a lsvtec with plans of boosting it. I am gathering the parts together. The turbo I have a Precision 3431e 57 trim .63ar and a "ebay" cast log manifold that has been ceramic coated. Would a 38mm wastegate suffice for a goal of 350-400whp? Or should I go to a 44mm?

 

Your. Or going to fit 44mm on a cast log. That being said the 38 should work just fine with that manifold

 

38mm will work fine on that turbo & manifold.

 

38 mm should be good but 44 woulding hurt