Just got my 454 back from the shop from being built. Stock bore, aluminum heads and intake, mild cam and roller rockers, 10:1 compression. He put marks on the the distributor as to where the timing should have it crank up at. Problem is it won't crank just back fire. Through the carb then through the headers. We walked the spark plugs back and they are right. It's like you don't get the trying to crank sound just backfire or nothing. I NEED HELP!!!

 

Sounds like you got the dizzy in 180 degrees off. Rotor should be pointed to number 1 wire tower with number one cylinder at TDC compression stroke.

 

You can hook up your timing light and check the timing as you crank (turn over) the engine. If the engine still acts the same with the timing where it wants to be, then it may be a valve lash issue.

 

Whoever rebuilt the engine probably lined up the dots with the cam gear dot at the bottom of the cam gear which is TDC for # 6 cylinder. He then put the distributor in with the rotor facing # 1 cylinder. He should have rotated the damper one full revolution and then put distributor at # 1 ( the dot on the cam gear will be at the top of the cam gear and the dot on the crank gear will be at the top of the crank gear). 180 degrees off.

 

That would do it too but you'd think a pro engine builder would get that right. Could just be the OP here just put the dizzy in at TDC #1 on the exhaust stroke not compression so I'd check that first.

 

Well, whoever put the distributor in wrong is dizzy. Maybe the engine builders name is Dizzy.

 

Thanks for the help it ended up being that the rockers were tightened down way to much. I got the motor back with the valve covers on it and had no idea they were that tight. Now i have a new problem. After I loosened up the rockers it cranked up I set the timing and it started right up. We crunk it up 7-10 times that day. I go back two days later and it won't do anything? It turns over and over but it's like there's no fire. I replaced the ignition coil. Haven't replaced the module yet but I know no other reason why I wouldn't be getting fire?

 

I'd be concerned about that build if the engine builder gave you back an engine with all the valves over tightened.
You say you loosened them? You mean adjusted them properly I hope.
Did you check for spark or just try to start it and nada>?
Is this an HEI distributer?