1979 RX-7 muffler needed
 

I have a 1979 RX-7 with 13b Bridge and 4-barrel Holley carburetor. Custom exhaust. Making high pitch squealing sound from current muffler. Rotary Performance says I need a new straight through muffler. Will be taking it to Kinney's in Watauga, TX in a few weeks to take a look at. Any recommendations for a new muffler? Kinney is suggesting Speed Demon product?

RacingBeat has a nice one thats rotor shaped too.

I have been told that Racing Beat muffler will not work on this set-up. This is a custom pipe coming off of a 13B and a 4 Barrel Holley!! There must not be any air flow restriction!

These, not the stock replacement: Exhaust Universal Parts - Early Rotary & 1979-85 Mazda RX-7