Heat Crossover Question

Does anyone have a preferred method or pictures for blocking the heat crossovers on 383/440? I understand the downside of closing these ports when it is cold but here in Phoenix I am having issues with hot starts given this generation of fuel. I see the the Fel-Pro gasket 1215 has them already blocked. Is that enough or could thr exhaust heat burn thru this gasket? Any info here would be appreciated.
Author: JBBQ