[stockapearing455]

I just installed my 455 which is basically a stock rebuild. I got it fired up, and after getting it to idle I noticed it would idle at 700 rpms and then out of nowhere rev up to 1200 then back down again. Almost like how you would do a quick rev on your motor.

It has 10 degrees initial timing.

Also too, im now noticing an occasional knock sound from the lower end of the engine. it has like one knock noise every 5 seconds.

I need some help. I have been playing with hot rods for 10 years now and have never had an engine rev on its own like this or have such a weird occasional knock.

Anybody ever seen this? Thanks.