Got Shell 93 Octane and now barely idles 1973 Dart 340

RustyRatRod said
No. This one.

http://www.summitracing.com/parts/edl-2732/overview/

Ok Thanks!. Will I have to change any throttle or the kickdown linkage? Why did the previous owner use 2 gaskets that look to be 3/8" thick, plus the thick adapter and RTV?

If I have to have someone drop the gas tank then I won't be too happy.