I believe your problem has a simple solution. To remove the front cover you must also remove the distributor. When the distributor was re-installed it was probably timed within factory specs. To get optimum performance you need to advance it until you get where it needs to be. I can't tell you exactly where it needs to be as every car is a little different. Just play with the timing and I'm sure you will get the thrill back... Just don't drive like that around me.