I just put a set of 1 3/4 slp headers on my 400 today and the car seems to go slower, im thinking its because im still using the stock junk Q-jet, also i cant check my engine codes but it like made a lower toned pop from the carb one day when i hit a bump and now it idles really low and the engine light is on all the time maybe thats the reason my car seems slower with headers from stock manifolds, its a 406 edelbrock heads 488-512 cam (low duration) edelbrock Performer and Q-jet for now untill my fuel injection, and its a pig, i think the intake setup is absolutely killing it, the headers made it want more fuel and the carb cant give it to it. or its because of the check engine light and extremely low idle now(5-700) or itll stall. no idea, but now it also pops loud when i down shift. not sure whats making the car seem slower, my dad also moved the timing a little but he said he moved it back but who knows if it was exactly where it was but even if it wasnt it shouldnt make that much of a difference unless its detecting spark knock and backing way off the timing. any help would be appreciated

 

You have to disconnect the tan wire near the distributor to set the base timing. Do a search and you will get more details. Get that quadrajunk out of there as soon as possible.

 

The LG4/L69 CC carb system uses a flat 4-wire connector that needs to be disconnected to set the timing.

You need to find out what's causing that engine light to come on. Check here https://www.thirdgen.org/newdesign/faq/thirdgen.shtml towards the bottom, it tells how to to do it without any special equipment.

 

Q-jet shouldn't be the problem. When you make extra power with a carb it simply pull more vacuum under the carb that gives it a stronger signal which pulls in more air and more fuel. I think you are going to have alot worse of a problem if you go to inject this car. That cam is too big for any factory fuel injection to handle. Your CCC q-jet is probably having the same problem, you need to burn a chip regardless.

 

I Have a burnt chip from John M and an LT1 intake w/ 24lb injectors for it. the cam is a low duration cam for the "TPI". i am going to try see whats wrong with it again today.

 

Also, i have a 4 pin ALDL not a 12 like it says, at least thats all the wires that are in it. but when i go from 5-6(i have a GM Code Key) it doesnt do anything. ill have to put up a post about this.

 

why not just put non feedback carb and regular hei distributor in it...wouldn't that be the easiest...can tune it all yourself then and no chips,,,

 

i could but later on im putting in a "TPI" system with LT1 intake so there's no sence in buying other parts that i wont need in a week.