Unfortunately I have to break down and make my first post, cause I can't find the info in search.
I replaced the 5.7TBI in my truck with a 400, and swapped the TBI stuff over to the new motor.
I know I may need bigger injectors, and some chip work to get BEST preformance out of this setup. And I know there is a difference between the 305 and the 350 knock sensors. But will the 350 knock sensor in a 400 give false reading, and retard the timing?
I've read that I CAN eliminate the sensor when I get into chip burning, but I would like to know if that is the only/best solution.

Bob

 

A simple data log will tell you if you're getting an abnormal amount of knock counts. What a data log won't tell you is if you're getting knock and the sensor is deff to it....in which case you're in the same boat as if you had disabled it.

If it does pick up false knock there are several things you can do to desensitize it. First is pick up a EST module from a CCC setup found on alot of the early 80's monte's and camaro's. Then if that doesn't work you can use a brass 90* pipe fitting on the knock sensor and that will desensitize it as well.

I wouldn't worry about it too much, in the scheme of things you need to be really concentrating on getting into prom tuning....there is a good possibility your going to loose power going to a 400 with out tuning, possibly even make it undrivable. Of course with tuning all will be right in the world of TBI.

 

I'm still reading up on chip burning, but before I get there, I need to have the correct hardware in place.
I've read that there is even a difference in knock sensors between an auto and a manuel tranny. Then a difference between a 305 & 350, makes me wonder if I can even use one on the 400. Are all the guys on here with a 406 eliminating it or are they using one, if so which one?
You are right about looking at knock counts to look for a problem, [don't have a laptop yet, so cant check], but that will not tell me which sensor to get to cure any problems.
thanks
Bob

 

You'll have to get into chip burning to disable the knock sensor anyway, so your best bet is to slap a 350 knock sensor in it and forget about it. There is a difference between the blocks but it really isn't that big of a deal. You'll get a check engine code if the knock sensor doesn't hear knock. The ECM has a routine that checks to make sure the knock sensor is there and working, if it doesn't see knock counts when the ECM advances the timing then it will lock the timing at 20 deg and throw a light.