i have a 408 stroker i recently put together it has eagle forged rotationg assembly with pro comp 210 heads roller rocker vic jr intake and pretty large cam. i had a 850 speed demon i purchased used and it seems to pour to much fuel in. i am wondering if i buy a new one or have that one rebuilt or what? any advice?
Carb help for 408 stroker
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mustangman9812
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i would run a demon 750cfm if it was mine. Demons flow about 100cfm more than they same so i always go lower in the size with them.
How about we start with what you already have. What do you mean when you say seems to pour too much fuel in? What does it do i.e. hesitate? buck? backfire? Is it out of the box stock or has someone had their hands in it? Depending on rpm the 850 is borderline too large but I'd bet with some tuning it would work. Mike
i am currently deployed in the middle east until october so i cant take it apart or anything right now but its an 850 speed demon that i bought at a swap meet and it floods the car. should i have the 850 rebuilt with differant jets or just pay a few hundred and get the right carb? if buy new what what should i go with?
I have a 408 with AFR205 heads and a Holley 950 HP carb and it's not too much carb for my combo, although, I am having other issues with high idle, stalling, etc. Besides the issues, I do not feel that cfm carb is out of line. The car runs pretty decent... I haven't made a full pass this year yet, but i pulled a 1.49 short time, and last year, I couldn't hook for the life of me, a 1.8 60' time and 10.62 @ 133mph. Once I get her back out, she's going run that low 10, high 9 pass... I swear!!!! 
Whats the compression of the motor, how many rpms are you turning it? Depending on those answer you may or may not have the right size carb. It does sounds like something is going on with the carb you have, a good rebuild wouldn't hurt and if it is too large you could sell it.
FWIW....I just got off a Stuska engine dyno with a 10.65:1 408, AFR205, Super Vic and a 750cfm Holley Street HP and I actually jetted it down 3 sizes to get it all into check.
FWIW....I just got off a Stuska engine dyno with a 10.65:1 408, AFR205, Super Vic and a 750cfm Holley Street HP and I actually jetted it down 3 sizes to get it all into check.
