4 inch Mufflex vs uncapped results inside

My LT1 makes close to 600 hp normally aspirated(I think)On pumpgas.

I have 1 7/8 headers, 3.5 inch Y pipe merges into a 4 inch Mufflex with a 4 inch Magnaflow single inlet/outlet muffler.

Runs the SAME with the y pipe out as it does with it in.

IOW, uncapped or capped up, runs the exact same thing.


David

Awesome. 600 on pumpgas nonetheless. What all is done to it?

Thats awesome to know. Do you have the part number for the Magnaflow muffler that you used to replace the Flowmaster?


Nick

Thats awesome to know. Do you have the part number for the Magnaflow muffler that you used to replace the Flowmaster?


Nick

Well I got it SOMEWHERE, it may not be a direct replacement, the tailpipe was fabbed up by me with bends and a turndown from an 18 wheeler dealer.

Look on Magnaflows site, they only make one round 4 inch in/out race muffler, the other one is oval shaped. Look in the race section of the site.


EDIT

Magnaflow only makes one LONG round 4 inch in/out muffler.