I plan on keeping the single exhaust with crossover on my f100 until I can afford the rams horns manifolds. I bought all new gaskets and what not but I noticed the passenger side manifold has a heat riser. I noticed the heat risor doesnt open up much. How much is it supposed to open up? Is there a way I can ditch the riser? If so what can I use and where could I get it?

For the thermastat what brand and what type should I get? It doesnt get too cold here in cali so I dont need anything crazy.

Fomoco Low Life