Elderbrock AVS carb

[cab4word67]

I have a used, rebuilt 1406 on my crate ZZ4 and for the past 15K it has never failed me. Stock fuel pump no reg and never had a heat spacer. And in my 65 mustang that runs hot under the hood with my fresh 289 built radical I have a new 1405 box stock without the heat spacer and again a stock fuel pump. Never hard to start. In fact I never have run the heat spacer on any of my cars and always run a stock pump, guess I am missing something here for the past 50 years