With the 1/8 scale I know a lot of Picco drivers using the Picco pipe and engine with a Novarossi manifold, it seems to work better.

If it is the shape or the total length I do not know but yes, it is an option to finetune the exhaust system to the engine.

I must say the 2033 pipe with the Nova short conical manifold is running great on my Nova engines