I know this is an old issue, and I did perform a search but I still had to ask: I have to choose between two ignition systems that I own. One is a GM HEI with a MSD6A and the other is a Mallory Unilite(I think it's the photo model). My two engines are SBC's, one is a 283, mildly modified(q-jet, Edelbrock performer dual plane, mild cam, 9:1 comp), and the other is a 350, more aggresive cam, Holley 750 DP on Weiand Team-G, 10:1. The 283 is in a fairly heavy car which is basically a street cruiser with an auto trans. The 350 will be used in a lighter, manual shift car. What distributor should I use on which engine?
mrl
Doc here, 
imp:
First you didn't say what car it's going in..
On the 283, If it's in the triple nickel series..(55,56,57) it's a foregone conclusion..the Stock GM HEI won't fit between the engine and firewall..you need a small body HEI for that..(or cut/Dent the firewall)
Again, the 350 depends FIRST on firewall clearance..
Other than that, it's a simple choice, put the more aggressive ignition on the more aggressive engine.
Docimp:
imp: First you didn't say what car it's going in..
On the 283, If it's in the triple nickel series..(55,56,57) it's a foregone conclusion..the Stock GM HEI won't fit between the engine and firewall..you need a small body HEI for that..(or cut/Dent the firewall)
Again, the 350 depends FIRST on firewall clearance..
Other than that, it's a simple choice, put the more aggressive ignition on the more aggressive engine.
Doc
imp:Eh Doc,docvette said:Doc here,
First you didn't say what car it's going in..
On the 283, If it's in the triple nickel series..(55,56,57) it's a foregone conclusion..the Stock GM HEI won't fit between the engine and firewall..you need a small body HEI for that..(or cut/Dent the firewall)
Again, the 350 depends FIRST on firewall clearance..
Other than that, it's a simple choice, put the more aggressive ignition on the more aggressive engine.
Doc
The 283 has lots of room for an HEI, it's in a 1962 Pontiac Stratochief, which is basically a Canadian's version of a Catalina. The 350 will be tighter (I am considering swapping it into a Volvo 740). So would it make sense to put the narrower Unilite on the 350? Or are you saying that the HEI with the MSD is a superior system to the Unilite?
mrl said:
Doc here,docvette said:
imp: When you speak of a 283, down here, most think of the 50's series Shoeboxes..not a Poncho..
But yes, If the 350 is going in a tight engine bay, it makes sense to go that direction..you really need to make measurements before setting in stone.
The MSD is a performance ignition..good to about 8500 RPM, The HEI is just that..High Energy Ignition..Stock good to about 5500 RPM..so yes the MSD is a step UP.
Doc
imp:ok, thanks. BTW, do you know what's the max rpm rating is for the Unilite?docvette said:Doc here,
When you speak of a 283, down here, most think of the 50's series Shoeboxes..not a Poncho..
But yes, If the 350 is going in a tight engine bay, it makes sense to go that direction..you really need to make measurements before setting in stone.
The MSD is a performance ignition..good to about 8500 RPM, The HEI is just that..High Energy Ignition..Stock good to about 5500 RPM..so yes the MSD is a step UP.
Doc
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