The holes are to let some exhaust go through then you adjust the springs for what rpm you want the flaps to open for racing.

If you don't or didn't have holes in the flaps, you had copies!!!

"Some, nor dime. Sorry. Slanted fingers on telephone keyboard."

What did you mean by this???
Jerry

Alot of times i press letter next to what i try to press. Some people call it fat fingering.

They looked like these

Those pictured are generation 2; generation 1 had holes in the plate only.

There is a guy looking for a set recently in this thread. Drew Marine 4” Shotgun Exhaust Tips

For SB's post, he meant to type SOME and not dime.


The earlier ones had holes in the flappers. The later ones had holes on the bottom