On my little 1.5 ecotec we adapted a 2.0 LTG throttle body to the stock manifold. That wouldn’t allow the stock valve cover breather to stay in its home. I ended up cutting about 2” off the stock breather and miraculously it was the perfect ID for 1/4” NPT threads. So new threads a few fittings and it’s clears the valve cover by about .001 and it clears the throttle body by about the same distance. Fun stuff!