I'm wondering what is correct diameter of the very last opening on original muffler end cap. Mine is hand made long time ago upon the old original muffler and diameter is 20mm (just above 3/4'). Does anyone knows exact number since I'm preparing to make new mufflers out of prochrome steel.
thanks in advance for any answer
p.s. I can and I have time, meanings and material for it

so, why not?