use a high speed dremel with the flex extender and a wire wheel and run it through as much as you can til its as smooth in there as you can possibly get it....you wont gain much but you will gain a little.... another option would be to purchase shorty headers, they're less in the way but they're still very much a pain to install on that car.... you will have a little more difficulty accessing the spark plugs, which i'm sure you already have some difficulty atm..... probably not as bad as my brothers maverick with the 390 in it tho