so yesterday i swapped a 350tbi truck intake manifold onto my 305, just had it lying around so figured i would clean it up and make the job of replacing the intake gasket faster, well since then i haven't been able to get it to run pretty much at all, i think its just a timing issue because it will crank, i have spark and fuel, and after a few cranks it backfires through the ignition. as far as the swap it should work right? thanks for the help Mike

Sounds like a potential timing issue. All you did was swap intakes?
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350 intakes will work fine on a 305 for TBI's. That shouldn't be your issue

yep just intakes + all the vacuum stuff, i figured it was timing i got it started the first time, ran like garbage my buddy said its running like that cause distributor was in backwards flipped it didnt start, flipped it again still wouldn't start

so i got the distributor in right, got it started had one hell of a spark knock so i keep adjusting it around and it doesnt matter how far i put it either way it wont stop knocking when i give it gas, even worse when i plug in the computer and its blowing white smoke out of the pipes and oil cap... any ideas?

Did you set the base timing? If so did you remember to unplug the tan wire over by the passenger side strut, before you set the base? Sounds like you just put the distributor back in without setting the timing.

Are the gaskets the same for the 305 & 350 manifolds? Any chance coolant is getting into the intake?

Believe it or not I just remembered a situation I had with almost identical symptoms. It was the coolant temp sensor (CTS). I swapped manifolds and all the sensors, fittings, etc and it acted the same way. A CTS can act the same way.

Give it a shot.

The first thing you need to do is set the timing. Anything else will lead you astray. If everything ran fine before the swap chances are it will run fine now. One more step in your intake installation procedure will net you a properly running car.

I do agree with getting the base timing set. CTS failure can cause a flooding situation and no start. Mine ran perfect before the swap, but you know how things go with sensors...

http://www.thirdgen.org/settingtiming

Make sure this is done 100% and check the obvious again such as plug wires, firing order, etc.

Let us know

Good point here. Make sure you didn't do something as simple as crossing a plug wire. It is very easy to do and gosh knows how many time I have committed this trivial mistake.

I hear ya! I have even had mine marked and still screwed it up. Once fatigue sets in the mind plays crazy games and we forget the basics especially for those where this is second nature to them.

someone PLEASE help. 85 305 TPI. Just bought ACCEL "dizzy" with cacuum advance (when stock is elec. advance) and I can't edjust it far enough to start it and I know it's at least a tooth off or right at a tooth. it hits the fuel rail. what is this i hear that u can point a dist. in any direction as long as TDC is good and plug wires go in corresponding places on cap? so does that mean that my dis. can point in any direction as long as rotor is toward 1 on cap and wires are good? it don't have to be facing the "factory" direction it does. cause if that's the case than maybe I can make this vacuum ACCEL diz. work. please PM ME IF POSSIBLE. thank u and God BLess All.