Timing Change or ???

Was running a 548" BBC with Dart 360's, 14-71@ 44% overdrive and a Mag 12... We were running 37 degrees of advance.

We are switching combo's some, and was wondering if I should change anything, or move the timing around.

It is a 526" Rodeck Aluminum Solid Block

Dart 360's flowed to 410

MSD 10 Ignition ( I have heard to lower the timing when swapping to the 10 from a Mag 12 )

We have a new camshaft going in at .833 on both sides, 282 Intake, 296 exhaust, and a 116 lobe seperation.... This is a change from an old turbo camshaft.

I have yet to buy pistons for the new motor, but we were running 11.5 to 1 before and unless someone thinks otherwise, we will run the same compression ratio again.... Any opinions on this?

Also, we have turned the overdrive down to 40% from 44% which didnt really make any change in boost.



Also, with the camshaft change, should we fatten up our tune when we first try it, or just let it go as is... We were only burning off around 50 percent of the cadmium before with the old setup.


So basically.... Should I lower my timing to say 34 degrees, Should I continue to run 11.5 to 1, and should I change my tuneup with the changes I have made.

 

you will always get different opinions on any question you ask, so here's my 2 cents. whenever we switch combinations we always try to stay on the safe side, until we find out what will make the motor "happy". that being said, here is my advice to you......
lower the timing to say .....34, keep the compression at 11.5 ( if this isn't enough, you could always put a little thinner head gasket on it later to raise the compression) fatten the main jet up .010. here's why i gave this advice.....
it will still run if it needs a little more timing, won't hurt itself with a little less compression, and it won't hurt anything if it's a little fat. if i were you i would take this and make it your baseline......tune your car from there. once you have everything perfect in the tune-up, and still need to go faster then i would consider changing other things on your car. in other words, just inch up on it, take baby steps.......i learned that the hard way
Darren Russell

 

My understanding is the MSD 12 is points??? Is that correct? If so the rise time of the digital ignition will be much faster which means, yes, retard the timing. With our 360 stuff and SM IV's, 37° is too much. You can run less, lean it up, make more HP and be easier on bearings. Not too many times that works out.
I would richen by .005" in the main and go play.