blocking heat risers

Say it's been a long time since I've posted anything and thought I'd post this question: Anybody out there block their heat riser ports with pennies in the top of their flathead blocks? I heard it's an old school trick. See I'm in the process of swapping out my single carb stock manifold on my 8BA with an Offy w/dual 94's and was wondering if blocking the ports make enough of a performance difference. Anybody block the ports any other way?

thanks

 

If you live in a temprate climate and dont need carb heat, go for it. If it does help, my "seat of the pants" didnt feel it.

I leave it working for any type of street car. MIZ

 

It's just supposed to *sharpen* your exhaust tone........helps you get that *flathead crackle* when you're being slowed by compression......

I haven't really seen all that much difference........

CB

 

It really made a nice sound, I can't say it unproved performance

My 2 cents worth.

 

Hey thanks for the replies. I think I'm leaning towards leaving the heat riser ports uncorked. If it's mostly a sound difference only, I like the sound I get already with headers and straight pipes.....nothing like the sound of a flathead right? Cheers fellas