hey, new to the forum. just finished building my 351C. the setup is as follows: .030 over flat top pistons(10.7:1), 4v heads, new valvetrain, hyd. lunati cam lift .525/.525 -dur. 242/244@.050" -LSA 108 <NOBR>degree</NOBR>, old school edelbrock torquer intake 600cfm edelbrock mech secondaries, msd 6AL box electronic dist. max angine RPM is about 6700. and to put the power to the ground im runnin an old toploader with a 9 inch and 4.56 gears. i keep fowling plugs, and it noses off real hard on the top end, any suggestions on tuning? thinking about a 650 holley dp?
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I would get a bigger carb for sure and mechanical secondaries would be good too. I would say at least a 650 mabey even a 700, with those gears you should be able to gain rpms real quick. Does it foul plugs worse if you let it idle a lot or do a lot of stop and go driving, or is it just as bad when you run it all out? What is your timing like and is your fuel system up to par for this kind of engine? What is this thing in by the way?
-Johnboy

 

the engine as a 351 cleveland, it fowls them mainly when im all out, timing is about 10 degrees advanced at idle and almost 50 advanced wide open, i think it may be advancing too far, im not sure how to adjust wide open timing being that there aren't any flyweights or springs to change. it also noses off really hard on the top end, last time a ran it fell flat on its face when i cought 4th gear. fuel system is stock, oem mech fuel pump, do you think i need to upgrade? thanks

 

You could try swapping power valves to lean it out at WOT. What kind of distributor are you running, on some you can adjust the vacuum advance by sticking an allen wrench in through the vacuum nipple and to retard the mechanical advance you can put in stiffer springs. It can be challenging to get a vacuum secondary carb dialed in right because with a big cam and a single plane intake you won't have the nice steady vacuum that you would get out of a stock engine, this would be the main advantage to mechanical secondary carbs. As long as you are fouling plugs at WOT I would guess your fuel system is keeping up, but might put a fuel pressure gauge to be sure. NEVER MIND ABOUT THE POWER VALVE EDELBROCKS DON'T HAVE THEM.
-Johnboy

 

i forget the brand of the dist, its electronic though, pulled the cap off, no flyweights the vacuum diaphragm moves a rod that advances timing its weird

 

You typically have to remove more than the cap to get at the weights and springs, and that sounds normal for a vacuum advance. There is a rod that goes through a hole and hooks to a base plate inside the dist and the whole thing turns to advance.
-Johnboy