I am putting a new Edelbrock Performer spread bore with a thermoquad carb. I need to know what kind of gaskets to use and what to do with the space at the to of the heads the intake does not cover. Thank for your help

318?

yes 318

Aren't there instructions (or if Lost, you could go to Edelbrock Online website.)

That said, my "guess" is that a standard Fel-Pro intake-gasket set for the 318 would work, but you should verify.

just a friendly

I put these on my 318; finally got the intake sealed compared to the tin gaskets.

http://www.summitracing.com/parts/FPP-1243/

I believe these are for the small ports, so verify with what you have.

What gap at the top of the heads?

Go to your nearest NAPA or Carquest and get some of the composite gaskets for it. They will work as well as any. I don't recommend using the tin gaskets though. As for the horse shoe shaped openings they are not ever covered nor meant to be. They are a air dam to help block heat build up and help disipate the heat in the heads between the heat crossover and two adjaceent exhaust valves.