Think of it this way, It aint gonna hurt anything to make function how it was designed.
Mine has never frozen up because of not having the riser connected. Once, my carb had gunk in its jet and it was freezing half the carb up. Properly adjusted and clean it should be fine.
It only makes a difference on warmup. Its a thermostatic spring not computer regulated! Then again I havent ever been peeking under my hood while driving down the freeway to make sure! Ive had mine disconnected all this past year with no problem or comprimised efficiency.
More of a personal choice on the manifold. Theres nothing wrong with the stock manifold and you can find parts cheap. I dont have an insulator under the carb on mine and it works great.
Mine has a 54 year old engine in it, I dont expect miracle break throughs in performance! I know better.
Good Luck! Jeff
