i know this question has been beat to death but let me ask anyway. i have just built a 396/375 engine in my 68 velle. here are the specs:

396 bored .60
L-88 hi-perf square port heads closed chamber
11:1 closed chamber pistons
COMP Cams Xtreme Energy CCA-11-770-8
COMP CCA-939-16 springs
COMP valve girdles and complete valvetrain
holley 750 double pumper carb
MSD pro billet (mechanical advance only) distributor 8360 ready to run
MSD 6AL ignition box
heddmann headers with 2 inch tubes and 3 inch collectors
3 inch pipes all the way back into 2 chamber flowmasters
3 spd automatic with 2500 stall
3.73 gear in the back

FULL BALANCE AND BLUEPRINT
i built this engine to turn 7000 rpm, and its overall very strong.

my question is, whats a good starting point for the timing? i have had some trouble getting to a spot where i think it should be making the right kind of power. right now i have 1 light silver spring and 1 blue spring with the silver (21 degree) bushing installed into the distributor. my initial timing at 900 rpm idle in park is 15 degrees. this seems to run the best out of any of the combos i have tried. should i try a more laid back curve with different numbers?

have any of you guru's out there found a good combo to start off with? can anyone make a guestimate at what kind of a advance curve i should use? i do not think i achieving maximum HP with this setup. what kind of HP can i make with this thing. should it spin through second gear? any tips would be great! thanks!

what else have you tried?

i would think a bit more initial, but you will have to watch your total..try 16, maybe 18..keep total no greater than 40.

vacuum advance?

no, i dont have a vaccum advance on it.

the only bushing i havnt tried is the red one(28 dereees)

is it better to have a mecahnical advance curve that moves out further over the RPM range, or is all in very quickly?

i know this question has been beat to death but let me ask anyway. i have just built a 396/375 engine in my 68 velle. here are the specs:

396 bored .60
L-88 hi-perf square port heads closed chamber
11:1 closed chamber pistons
COMP Cams Xtreme Energy CCA-11-770-8
COMP CCA-939-16 springs
COMP valve girdles and complete valvetrain
holley 750 double pumper carb
MSD pro billet (mechanical advance only) distributor 8360 ready to run
MSD 6AL ignition box
heddmann headers with 2 inch tubes and 3 inch collectors
3 inch pipes all the way back into 2 chamber flowmasters
3 spd automatic with 2500 stall
3.73 gear in the back

FULL BALANCE AND BLUEPRINT
i built this engine to turn 7000 rpm, and its overall very strong.

my question is, whats a good starting point for the timing? i have had some trouble getting to a spot where i think it should be making the right kind of power. right now i have 1 light silver spring and 1 blue spring with the silver (21 degree) bushing installed into the distributor. my initial timing at 900 rpm idle in park is 15 degrees. this seems to run the best out of any of the combos i have tried. should i try a more laid back curve with different numbers?

have any of you guru's out there found a good combo to start off with? can anyone make a guestimate at what kind of a advance curve i should use? i do not think i achieving maximum HP with this setup. what kind of HP can i make with this thing. should it spin through second gear? any tips would be great! thanks!

madlag,
I'm also running L78 in my 66, and I have the initial is at 18 degrees, no vac advance, and 36 total @ 2800 rpm.idles at 950 rpm in neutral. and naturally running hot gas.
This motor likes lot's of initial timming, my other big block in 55 also does.

your motor should really run, give her lot's of timming :yes: experment with her, untill she ping's. keep playing with distb.
just my thought's

mrchevelle,
what spring combo/bushings are you using to achive this?

the way i see it, use the black bushing(18 degrees). the closest thing i see to the timing curve is using 1 heavy silver, and 1 light silver spring. does this sound correct?

I'm at approx 21-22 initial with the black bushing limiting mechanical to 18 with a heavy/light spring combo in my billet MSD. You're going to find out that engine is going to love timing, give her as much as she'll take without pinging and choose your bushing accordingly. Youll decide on the springs correct for your application through trial and error. Make sure you've got a good starter and some heavy guage battery cables too. good luck.

I have 1 67 chevelle ss,with a 65 396/325 engine,the motor is stock except for a mild cam(thats all I know) when I try to time the motor at 4 degrees (btc)the mark is way above the scale on the timing cover,I try to bring the mark to the right position but the engine barely runs.I have to time the engine by ear,but the engine pings,I know the gear marks are positioned correctly,and the dist is in properly ,the vacuum advance is disconnected,could the springs in the dist cause me not to get the stock factory timing?

I have 1 67 chevelle ss,with a 65 396/325 engine,the motor is stock except for a mild cam(thats all I know) when I try to time the motor at 4 degrees (btc)the mark is way above the scale on the timing cover,I try to bring the mark to the right position but the engine barely runs.I have to time the engine by ear,but the engine pings,I know the gear marks are positioned correctly,and the dist is in properly ,the vacuum advance is disconnected,could the springs in the dist cause me not to get the stock factory timing?

4 degrees advanced is a stock timing number. Back in 1967 when we had 100 octane gas. These guys are timing the engine at 15 to 20 degrees cause the crap gas we have now needs longer to get lit and burn. The springs dictate how fast the mechanical is going to come on. The different combinations get you what we call "all in" (full mechanical advance added to the initial) at different RPMs. Personally I like the all in at 2800 to 3000 RPM). The bushing sets how much mechanical advance is added to the initial when it all in. For example, 136679ss tells us he is running 21 to 22 degrees initial with an 18 bushing so he is at 40 degrees all in.

Gary,Thanks for the reply,I am a weekend mechanic,my intentions is to have a stock chevelle ss,I am trying to keep the engine stock also. I replaced the headers with the stock manifolds,also removed the hi-energy dist with the conventional dist. My Question is with everything being stock can't I retain the original factory timing settings (4 btc),I am not looking for performance just originality.When setting the timing I can't get the timing mark near to the scale. Again I know the dist is in correctly to number one,and the timing geras are dot to dot.I don't know what are the bushings you are referring too in the dist,unless you mean the advanced weigh springs Thanks Again

Gary,Thanks for the reply,I am a weekend mechanic,my intentions is to have a stock chevelle ss,I am trying to keep the engine stock also. I replaced the headers with the stock manifolds,also removed the hi-energy dist with the conventional dist. My Question is with everything being stock can't I retain the original factory timing settings (4 btc),I am not looking for performance just originality.When setting the timing I can't get the timing mark near to the scale. Again I know the dist is in correctly to number one,and the timing geras are dot to dot.I don't know what are the bushings you are referring too in the dist,unless you mean the advanced weigh springs Thanks Again

Nope. Sorry. Certainly appreciate the desire to have a fully stock car but 4 degrees isn't enough even if everything is stock because of the gas you have to use. In 68 we were burning 100+ Octane. It lit fast, burned fast so lighting it 4 degrees before TDC was what you wanted. As the piston went over TDC and started down on the power stroke, the 100 Octane was burning fast enough to make max power. Now? Now we have maybe 86 or 90 Octane if we're lucky and it's much slower to light. If you don't give it enough time to get lit by advancing the timing (i.e. lighting it sooner), then when tries to make power it will be still just lighting up rather than being lit. Ergo the motor runs like crap. Not because there is something wrong with the motor but rather what you put in it.