Hello everyone,

I have a 71 chevelle with a 350/350 combo. I attend college 300 miles from home so fuel milage is important...this means performance doesn't get the attention I'd like to give it.

The engine has a mild build that includes a bore, 4 "eyebrow" pistons, 268 cam, edelbrock intake (not marked as performer, unsure what it is, was on car when i got it), Holley 650 spreadbore w/mech secondaries, headers, Holley Powershot 14x 3 drop base filter, Summit HEI cap and rotor w/50,000 volt coil, MSD super conductor wires, all running to a trans that came in the car that hits 2nd barking the 3.08 eaton posi enough it scares me something is gonna give...

anywho...I'm debating pros and cons of a MSD 6A or 6AL box. With this mild build would it make enough difference to justify $200?

I haven't had the car on a dyno, my dad built the engine and estimates about 310 flywheel horsepower. I know its not accurate whatsoever to compare but 2003 stock mustang gts with autos can't catch me till after 80.

Any advice is appreciated

I think it will help most motors. You never know you may upgrade the engine one day, then you'll have your ignition out of the way, apart from a good distributor, coil, etc.

Won't help you a bit,as long as your ignition is in good working order it won't do a thing for you. I doubt that it would help me any,but the rev limiter would be nice to have.

Absolutely positively will not help performance. It is just another part that can fail more... electrical connections to play with and a waste of $200 from a performance standpoint.

Buy the MSD rev limiter for $99 that fits the HEI. That is a smart investment.

Use the $100 you save to buy accelerator pump squirters and pump cams, power valves, a jet kit, water wetter, a carb spacer after borrowing a few, a better helmet, line loc if you race..etc., etc., etc.. a good trans cooler

One of my favorite stories that I've heard at the dyno facility is: how often they get a car to run better on the dyno by DISCONNECTING add on ignition boxes. What happens all too often is that someone will add an ignition box at the SAME time they replace cap, rotor, wires, plugs. So of course the car runs better - not because of the ignition box, but because other worn parts were replaced. Oh yeah, the mileage increase many people attribute to add on ignition boxes are more correctly attributed to the other new ignition parts, or to subtle changes in driving style while they are paying attention to fuel mileage.

There are some aftermarket "performance" parts that exist soley because the public will buy them. Keep in mind for instance that your "50,000" volt coil will probably never be called on to deliver that kind of voltage. My '65 has a 37,000 volt coil and I'll bet it has never run up that high - even at the drags.

Thomas

Thanks guys! Glad to know I'd be better spending the cash on the rest of the junk I need for my tach cluster to replace the stupid idiot light set up...