ZL-1, MSD
 

My ZL-1 engine "loads up" when idling or driving in traffic (cruise night only). Would an MSD unit (I would use the GM version 10037378 if compatable with TI ignition) help this problem? Engine is all ZL-1 including cam, carb. Thanks.

Re: ZL-1, MSD
 

No...what plugs you running? Also, how is your carb set up?? Your powervalves in good shape???

Re: ZL-1, MSD
 

Plugs are stock AC-R43XL, carb is stock Holley 4296 set up, power valves are good, cam is stock ZL-1 with 260/270 @ .050 duration.

Re: ZL-1, MSD
 

My first suggestion would be to ditch the AC plugs and try a set of NGK v-power plugs...if they don't clean up your idle, then you can definitely look elsewhere.

Re: ZL-1, MSD
 

Thanks, those are great plugs.

Re: ZL-1, MSD
 

Rob what are the NGK plug numbers for an L-72?

Re: ZL-1, MSD
 

In our 840 heads we run the R5671A-7, and I believe we run the UR5 in our 291 heads...