Exhaust Question

[weaseltree19]

Hey all,

So I've got a 1979 cb750 here.  Im not certain if the exhaust is stock or not, considering that the previous owner tinkered with it quite a bit.  When i remove the muffler I can see straight through it, so no baffles.  Is this stock for the 1979 cb750 K's?  I dont want to mess with carbs and am still running with the stock airbox as well.

[weaseltree19]

Im also running a 4 into 1 system.  My exhaust looks like this one.  I wasnt running stock airbox in this photo but am now.  The muffler was powder coated black, was originally chrome.  I would really like to be running the stock exhaust, just for the well-being of the carbs.  Im assuming that the open pipe is NOT stock for this bike.  Does anyone know if this Vance and Hines baffle insert will work well with a 1979 cb750K?  
https://www.denniskirk.com/441361.sku?utm_source=google&utm_medium=cse&gclid=Cj0KEQiAzsvEBRDEluzk96e4rqABEiQAezEOoLp33CZLs5jDLNOF9kNjHwF4sG6w_bUyL3y8enEfZ0AaAtGC8P8HAQ&ad=45713334277

[TOOLS1]

That is not a stock exhaust.The exhaust does not have much effect on carb tuning, as compared to the airbox. You can install any muffler you want onto the collector.
TOOLS