they have a couple rev limiters on ebay for like 10 bux. I was thinking i should stick with the vaccum dizzy, just wanted toi make sure i was correct. And that truck hauls a load whenever it rolls. lol. im turning 38.5's on stock gears. One day i'll upgrade to a sterling 10.25 and a dana 60. thanks for the info guys!!

heres a linnk to the limiter.

http://i3.ebayimg.com/03/i/000/aa/d3/366b_1.JPG

 

They make a box that has a built in rev limiter and that unit which is an add-on, both use the same kind of chips, they are white, about 3/8" wide, 3/4" long and have about 10 metal prongs on them. they are usually sold in a kit.

I use the Crane systems which have an infinite control dial, I like that system better.

 

see i got that 6a box today in the mail. It has a place for a rev limiter. if the guy takes my off i'll only have like 50 bux in it. then the dizzy and maybe wires and i'll have a complete msd ignition.

 

You are better off with the factory duraspark II distributor, its already built and curved for your motor, not that its that difficult to do with the MSD, but its tuning that takes time and effort that you can put into things like burnouts and mounting the beer cooler in the cab.

 

So u have to recurve the dizzy. I figured if i got one for a 351mit would already be curved. And let me get another thing straight. When i put my 6a box in i unhook the factory ignition box right? And if thats true then all those wires in those two plugs run the ignition system??

 

Yes, the factory box is disconnected, you'll have to splice in the wires from the MSD box. You need to solder these connections, any kind of resistance or bad connection be subject to harsh vibrations and it won't last.

Technically, a distributor should be curved when any kind of performance mods are added, new MSD distributors are simply set in the middle of the road, it'll most likely run with that setup, but not very well.

The same distributor fits a 351M, 351C, 400, 429 and 460, so you can imagine why they need to be curved for proper performance.

 

alright. what if i buy a used one? Can i recurve it or once it curved it curved?? And Btw: i appreciate all this help, im new at this kinda stuff.

 

if you are saying that the holddown bolt for the stributor is broke, my friend it sounds to me like you aer getting some mixed timing from the stributor moving around, sounds like its retarded to me,

 

The screw that holds the pickup and vaccum thing, It has a screw and a zip tie holding it. The mount is broke, So i figured if i just got a msd dizzy i'd have the complete msd ignition system. It runs fine but i still think it needs the be adjusted correctly so it'll run at peak performance.

 

I have had a lot of experience with MSD's and timing on these motors and on low comp 460's. In fact I think I have about 3 of the 6A's out back in the tall grass. Maybe even some of the limiter chips. Very busy lately, but will attempt to look if you need lower rpm chips--actually plugin modules.

At this level, a set up Duraspark will do just fine as will the stock dizzy with good bushings. In a 79 bronco w/400 (edlebrock & 4300 carb or holly) and a crane "blazer" series cam that is very similar to the comp 270M cams, the MSD did make a large difference in idle/off idle performance and smoothness. Did not do a great deal for the 460 van as far as performance goes with stock cam.

A very large part of performance from these engines is in the timing. Most people do not understand that timing is a "system" and not just a simple setting. You must know and co ordinate all the portions of the "system", initial (crank), centrifugal, and vacumn. There are some principles of "swirl" and "mixture" that have a large effect on the amount of timing tolerated for any particular engine. First of all, too much will Ping (spark knock). Thats different from "detonation" caused by hot spots etc. It really requires a lot to fine tune the timeing for a street engine that may or may not be "loaded" and you dont want to get out and retime every time you haul something.

Heres what I liked to do with my timeing--
1. Only about 10 deg on the crank for ease of cranking, expecially when towing in hot weather.
2. Very light springs for cent. advance. I like it all in by no later than 2500 rpm. limit it to ~23 deg (total of 32-33 deg). This is about all you can stand for heavy loads on pump fuel. (no vacumn on a loaded engine)
3. Use vacumn for the "no-load" cruise economy. Limit it to about 5-8 deg. (yes, do some shade tree adjusting). That puts you at 38-40 degrees total. Yes, absolutely, you must loose the vacumn portion under any kind of load. set the threshhold such that vacumn drops off soon as the manifold vacumn drops even 5 psi. This can also be done on a stock dizzy---I have done several.

The biggest single seat-of-the-pants improvement came from lots of low rpm timing. No, you will not burn holes in the pistons---I checked mine regularly for about 150K miles and on several vehicles. Do not simply go and twist the dizzy or screw with only one part, you must do it together or you will have problems, pinging is just one!

Betcha I get some challenges on this one---thats O.K. but be nice BTW, my figures are not absolutes, but will vary.

 

When my truck was cold I had the popping when I got on the gas. I changed the plug wires and it fixed it. Is it worth getting an aftermarket coil(msd)?