Exhaust Port Plates

I used port plates in a built Boss 302 motor about 20 years ago. Back then we didn't have dynos on every corner like we have now. My butt-dyno couldn't tell the difference and my times on a race course didn't change. I also had a set for the intake side I added later. Again, no change I could tell. The thoery was that you were trading flow for velocity on the intake side anyway.

I bought port plates, but they were much different from the ones that are offered in this ebay ad. I bought port plates that were connected as one for each side of the heads. They were used and I paid $50 for them. The reason I bought them was because I changed out the stock 4-V heads for the 2-V heads thus the port plates were on the exhaust side for the headers. I also changed the cam and intake and there was a very noticable difference in POWER.