another timing question

Ok, i've been searching for the past week to get a general idea of where to time my 400 sbc, right now it's sitting around 16......but i keep hearing that 16 is ok, just as long as it's no more than 39 overall. What does that mean, what other numbers factor into the equation that i'm not getting?? Is it when the motor advances when revved? Also, how do I tell my overall number is? Any help would be great, I replaced the gaskets on the intake and after reassbembling the intake and dropping the dist. back in the 400 seems to be running hotter and less oil pressure, everyone that listens to it or times tells me it's perfect, but i still think i'm off somewhere....the motor seems sluggish on take off and at higher rpms. I really wish i could tell you my excat cam specs, but i have no clue......when i bought the motor the builder said something about .510, not sure for what though.....also i have an Accel HEI dist. edelbrock carb.

Ok. 16 means 16degrees BTDC on idle, and 39btdc at full rpm. the .510 means .510 lift on the camshaft. remember, when timing, remove the vacuum advance if installed. Possibly the best way to time a motor is with a vacuum guage. Install it on a manifold vacum port, and turn the distributor untill you reach peak vacuum. This should put you in good range. Drive it, and fine tune as needed.

Use a timing light when you time your ignition, not a vacuum gauge. Lots of people time their engine by ear, but that doesnt make it correct either. A timing light will tell you for sure where you are.

hey guys, thanks for the info.......really helps. I went and got a timing light and plan on timing it tonight. How do I know if i'm exceeding 39 if my marker only goes to 16? kinda guess I assume.

If you use a standard timing light, try and get a timing tape that goes all the way around your balancer, it glues on....I use clear nail polish to seal it on when it's on. That will give you 360 degree measurements. The other option is to get a dial back timing light. You set the timing on the dial, for ex. 36 deg., and then when you look at the zero mark on your balancer and they line up, you're there.

awesome, you guys are great. I'm trying to learn everything I can about engines......this is great. Thanks.