Exhaust tip inlet size

i could be wrong but i think the factory exhaust was 2 1/4 to the muffler and 1 7/8 (tailpipes) from the muffler to the tips.The tips were 1 5/8 slipping inside the 1 7/8 tailpipes.Don't worry about flow this far back.The factory realized the exhaust had cooled by the time it got that far away from the engine and performed fine on stock or slightly warm builds.