OK here it goes-
Kohler in general is bad FOR NOT FLOWING from the factory...This presents an issue with trying to build up compression.... It will KILL EVEN MORE FLOW!!!
So you really need to open up the ports.... Not to big but slightly large.... When you do this you are going to need more CARB so maybe get a #30 Bored out from Brian Miller or even a #26 Bored will flow just as well as a stock #30 (kohler Carb)
Now the heads............. Well shave them... Use the old clay trick put some on the valve with your head and head gasket on... See how much valve clearance you have....
ALOT of people are taking the Kohler and when they build a high-pro engine they will eliminate all the flow above the valve so it all goes under.... In this case you might want to change your valve angle from either 60 or 45 (cant remember stock? Help me out) and you want to change it so that when the valve opens Fuel can get in ALOT faster and sooner.
As 300xdeere mentioned above if you don’t have a good valve job it just is not going to run!
So really you want to have a good valve job period…. What I did is I found a DIRT-cheap valve machine and played and played around with different angles until I found the best power. Kind of like they use to do with the Ford Flatheads back in the day!
Now on your dual plugs yeah go for it! I run them and can’t be happier! I use a system called Dual Point Saver from
http://www.kirkengines.com/ …
I’m not sure if your Magnum has these type of points that are on the K-Series but this would work great for your dual plug setup! Also you could try a Crank Trigger Ignition (CTI).
Last thing- when you shave your heads make sure you take a little off the block for some extra TQ….
If you have any more questions you can email me or send me a PM here.
-Outlaw