What should my initial/total/mechanical timing be at and need help gettin there

[oldblue1968chevy]

At idle 750 rpms or so 29* (no vac adv)

At roughly 3000 rpms I get 39* (still no vac advance)

Street driven 100% 67cc summit/vortec heads flat tappet 279 comp thumpr 373:1 non posi 3spd manual 355 4 bolt main performer rpm intake 600 1406 edelbrock

This is all street driven DD

At idle 750 rpms or so 29* (no vac adv)

At roughly 3000 rpms I get 39* (still no vac advance)

Stock hei non adjustable vacumn advance. Do i need an adjustable vacumn advance? Also have a curve kit I can use.

What should I be set at (total/initial/mechanical/vacumn)

Thank you..

[Marv D]

'TYPICAL' Chby sbc timing curve is 10-12° at idle, add 24° mechanical all in by 3000-3200rpm (for total of 36°) , Vacuum advance is 'typically' 6-10 degrees. Some motors will like the added advance from Vacuum ONLY at cruise part throttle cruise (using ported) and are not sensitive to spark knock as you ease into the trhottle. Others,, HATE it. Those tend to work better on direct manifold vacuum so advance drops off as you open throttle blades.

How to achieve that,,, There are few real distributor machines around any more. I know of a couple that were bought as 'service' stations were closing and going to self serve. Also check with Dave (HEI,, umm HEI 454,, or 245 or,, well just look in the engine section, you'll find him) I'm sure he can fix you up. If your willing to wait for shipping.

[oldblue1968chevy]

Ok, i'll look for 'dave' lol

Right now WOT I have 36* with no vac adv idle is 14* with no vac adv

This is achieved with mr gasket weights and 1 big 1 medium spring.

Ive been using manifold vacumn for the vac advance

Is there anything i should buy that i need for this

(adj vac adv, vacumn limit plate?)

Sound right?