:?: The butterfly clip attaching the engine block heater inside the block failed on the freeway, leading to overheating and a warped head. The head, cam shaft, etc. was replaced with a (good) used unit and the engine block heater was replaced, too. As you might guess, this was pricey ($2400 CDN).

Since then, the air conditioner doesn't work the same - engine hesitates/falters when its on and its not as cold. Also, on the freeway the engine won't go into top gear. Instead it stays in 4th at high revs. Any ideas/suggestions as to whatsup would be appreciated.