440 Starter Opinion

Any one have heat soak on hot restart problems , that have found a cure/ my powermaster spins the 505 great , untill I try to restart it hot, hit the key , nothing , release and hit it again will crank and start, but seems to be getting worse/weaker ------------???
What style headers do you have, Under chassis? Have you got enough room to fit a 3/16 plate of aluminum in between the tube & the starter?