318 timing question and upgrades

[Savage6]

Hey guys,  i have a 1974 charger with a  318.  It has a purple shaft cam and a Holley 4 barrell carb..It also has hooker headers and flowmasters.  I have the initial timing set at 10* right now but it seems to idle much better somewhere near 5*  I'm pretty sure the heads and everything else are stock.  The car is new to me so I am still working on finding out exactly what I have and what I need.  I'm open to any suggestions for new heads or anything else that you guys think would help out with performance. Oh one last thing.. should I keep the vac advance plugged or connected??  Thanks again guys

[Plumcrazy]

Do you know which purpleshaft cam you have?    It would tell you if you have the right camshaft for your application.

If the Holley is somewhere in the 600 cfm range and it's on a low profile intake like the Edelbrock Performer then you've got a good combo there.

If you want to move up to a fairly cheap head upgrade, look for a set of swirl chambered heads from a late 80's 318.   I believe the last three digits of the casting number are 308.

If it's a street car, leave the vacuum advance hooked up.  Centrifugal advance adjusts the timing based on engine rpm.  Vacuum advance adjusts the timing based on engine load.  You want both on a street car

[Savage6]

The swirl chambered heads sounds like a good plan to me.. if I can find a pair someplace..  I think the carb is a 650 and the intake is the performer..  I reset the initial timing to abou 8* and reconnected the vac advance.  It is running pretty smooth and actually has some good power..  If I can get my hands on the swirl heads I think I might have something... Thanks for the advice p_crazy

[Foreman72]

cheers for guys w/318's in their chargers   i'm hoping to get around 400 HP out of mine ...unfortunately it won't make that much @ the wheels due to its hugeness...its gotta be hard work for an engine that small to move 3000+ lbs as quick as i want it to haha...but anyways...this is what i'm going to model mine after..

http://www.popularhotrodding.com/enginemasters/articles/mopar/0667em_mopar_318_engine/index.html

i really liked what i saw..so thats going to be my goal.

If you want to move up to a fairly cheap head upgrade, look for a set of swirl chambered heads from a late 80's 318.   I believe the last three digits of the casting number are 308.

i think it's 302 castings...thats what i've heard everywhere else...

but yeah mopar mills are pretty soild stuff...doens't take much to bust em open...now you just have to look @ the rest of the driveline huh...