93 s-10 header dual exhaust problem

i have a 93 s-10 with a 4.3. about about 3 years ago i added edelbrock tubular exhaust headers and duals with only resonaters on them. just recently i started burning threw the lead donut gaskets between the heads and the pipe. i finally went and got steel ones and replaces the studs and bolts but it still is loosening up i those steel gaskets are expensive. any one know what i should check on?? someone told me that i might have a sticking egr but it looks like its operating just fine to me. well let me know please, thanks