I can't find a way to get to the small valve on the firewall that controls heat to the cabin. My arms won't bend that way either through the top of the engine or from underneath. Do I need to take something off the engine first?

This is worse than trying to get to the back spark plug on a '77 Chevy Monza!!!

easy way is to remove the intake log along with the short stacks, Unbolt by removing the 12 acorn nuts, Do not atempt to remove by loosening the hose clamps on the boots, there is not enough room

Will try this.