hey i got a 74 390 FE in a 1977 F-100 4x4 shorty an i my engine is pretty well all new, had to buy a new block. luckly found a short block all done up. bore 30 over, flat top pistons, an thumper cam. seen the receite of the work an was up to 3000 bucks. well i got the short block in an everything on. an im gettin fire, timings good, gettin lots of fuel. got a brand new 600 cfm carb. an the odd time it will start an soon as yea play with the adjustments an timing it would quit. its like its flooding its self of not gettin enough fuel. its coffin an farting like it wants to go but nothing. we though rotton fuel but 2 days ago we had my old 390 running an driving but the bottom end let go. an we dumped fuel down the carb. just woundering what were doin wrong.

an also i just woundering what the degree offset on the timing chain has anything to do with it? the timing chain was already on it but had to change the dowl pin an set it on 0. dont know since having the thumper cam have to offset the sprocket. an dont know much about the degree offset for the timing chain.

 

Start by running the timing chain straight up, 0 degree offset.
Sounds like a timing or firing order problem. Double and tripple check that the firing order is correct. After you're sure about the firing order double and tripple check the timing. Make sure when you're setting the timing that #1 cylinder is TDC on the compression stroke and not the overlap stroke.
If it still doesn't start and run then check that it's getting fuel and the float level in the carb is correct and not sticking making it either starve for fuel or flood.
BTW welcome to FTE, there's a lot of good, knowledgeable people here that are more than willing to help.

 

k thanks ill give it a try

 

Check your firing order. If you swap #6 and #7, or #2 and #3, it'll almost start but cough and backfire. 15426378.

 

Yea we tried everything an was only gettin fire here an there so changed the pick up in the stribitor an plugs wires an cap. An still got nothing. An we towed it thinkin would go cause the starter gettin weak. An bout the only think I haven't changed is the ignition modular box an the resistor on the silonoide
Sorry for the bad spellin lol

 

got the truck running after changing the ignition modular box an ran fine for a bit an now at the idol it knocks. think like a spark knock or pistons hittin the valve or something. an the knock goes away after giving it some throttle an the timing is fine