my m-6007-f460

i have the m-6007-f460 crate that came with the msd 8580 this is mostly street so i would like to go to my msd 8350 with vacume advance. can i get a suggestion or a starting point for my total with the v/advance, i am at 32 total right now with the 8580 and will stay with that number (mech) in the 8350. looking for a good base cruise number..

under steady highway cruise conditions; the mixture is lean, takes longer
to burn, the load on the engine is low (it only takes about 40 horsepower to cruise at 50mph) and
the manifold vacuum is high, so the vacuum advance unit is again deployed, and adds 15 degrees
of spark advance over and above whatever the distributor centrifugal advance mechanism is
providing at that engine rpm. If you had a timing light connected so you could see it as you cruise
down the highway, you’d see about 45-50 degrees of spark advance; your fixed initial advance of
10 degrees, 20-25 degrees provided by the centrifugal advance mechanism, and the 15 degrees
added by the vacuum advance unit. i'm good....thanks

30 to 32 mechanical ... vacuum advance only adds advance at part throttle so it doesn't change the required total mechanical advance number for Wide Open Throttle. It is limited by whatever the engine will accept at whatever the particular RPM so, the quickness of the mechanical advance curve plays a big part in what the vacuum advance should be.
45 to 50 degrees is not uncommon at part throttle cruising with very low mixture density and low compression or high valve overlap engines.

thanks randy.... update, the vac/advance added 12 degrees for a total of 43 when cruising and there is gained torque down low. where i really needed the improvement was during cruise, this solved my 5th gear issue, anything under 2 grand in overdrive was a bit to doggy now 1500 and above is great! because i didnt have alot of experiance with the vac/adv. or how it operated i ran a hose from the intake (minifold vac.) into the cab hooked to the canister and drove around, i was suprised by how often the vac/adv. was in the on position. i also wanted to be sure i had enough vacume to activate the can properly, my motor pulled 12 inches and a best of 15 while cruising. having fun with this experiment and just wanted to share..

Good to hear.