Hi guys. I took the Chevelle out yesterday and it started to break up around 4000 rpm and pop back through the carb. I think its something possible with the mechanicial advance. (Intake open during the combustion stroke). Anyway, I have been thinking about getting a new HEI distributor for awhile, and now seems easier to justify it to the wife. Anyway, who makes a good one? Who should I look out for? Should I get an MSD box (don't have one now)? What are the a benifits with one of the boxes (6A, 6AL, 7A ect). It's alot of questions, but I can appreciate any advice.

What distributor do you have now? I do not run an ignition box, but will probably be investing in one before long,if for nothing else but a rev limiter.

I would get an Accel,Mallory or even a Summit HEI..anywhere from $100-150
You do not need some overpriced,over hyped distributor.
The MSD 6AL is a good choice for a 4 speed musclecar for the rev limiter feature.

..sounds like your current distributor needs a new set of points.

I have just a stock HEI distributor, and was thinking the box just so I could have the rev-limiter. So basically any distributor in the Summit catalog will do?
Chris

Red,
There are guys running the stock HEI's up to at least 6000 rpm without problems. I doubt seriously that is your problem unless something is actually wrong with the distributor. As far as a rev limiter goes, on the cars that have them they are not in the distributor, they are in the ECM.

Originally posted by RedSS454:
I have just a stock HEI distributor, and was thinking the box just so I could have the rev-limiter. So basically any distributor in the Summit catalog will do?
Chris Since you already have an HEI,why not just get the MSD 6AL box..I was under the impression you had points since you mentioned it was breaking up at 4000 rpms..sure you don't have a fuel delivery problem?
Hook up a timing light and check your timing to see if your mechanical advance is working.
If you do need to purchase an HEI,the part # is SUM-850001R for the Summit one.

I'm sorry. I guess I never really explained the problem. I got a 454 with unknown internals. Stock HEI distributor. The car runs like a scolded cat. Chrips the tires on the 1-2 and 2-3 shifts. So, before the winter, the thermostat was starting to stick. We replaced it with a 160* thermostat. So we tucked it away into the garage because of the snow, and it rained all week and we took it out yesterday. Had it ideling in the driveway for awhile while I moved the other cars around, and I heard BANG out the right tail pipe. Sounded like it was loading up. So, I drive it away slowly after a few minutes of warming up, and it almost feels like it is "surging". After it warms up, it runs GREAT up until 3500-4000 RPM. When the secondaries kick in, it starts to pop and fart back through the carb. Has never done this before. Thats what has led me to believe it is something with the timing/distributor.

I had a similar problem with a 67 Chevelle I had years ago. I would break up like crazy once the secondaries came in on the Holley. I couldn't figure it out for the longest time until I popped the hood one night to show a friend what I was talking about. Well it looked like Christmas under there with the plug wires arcing all over the place. I would be willing to bet that your wires are bad. It was the same exact problem as you are describing above. Hope this helps ;)

Originally posted by cromedss:
Hope this helps ;) It more than helped, it fixed it! Pulls up to 6000 now. I am going to have to buy some new wires, but it is back to its old self. Wish every problem was just that simple! THanks for all the help guys.

i went from stock points to a Mallory HEI and MSD 6AL...i dont know about other guys luck with these products but i dont reccomend them at all....the msd box burnt out and the car died on the street and the distributer has such a design under the cap that it makes it hard to connect the wires...took it to my mechanic and he threw the box and distributer away and gave me a rebuilt hei...starts right up and revs hard

I experienced a New distributor to hit the market and WOW, what a difference. My vehicle ran very strong with what I had (MSD billet distributor, their timing computer, 6AL & blaster coil) I installed Crane Cams new Street/Strip billet distributor with adjustable electronic advance + map sensor for vacuum assist. HEI, like the MSD use old school springs & weights advance mechanism. These tend to stick, wear pins,etc. Note, if you check the advance on a distributor machine, just removing (streching) and install the same spring back-on will change with advance rate! I installed the Crane distributor, turn the dial to match the MSD timing computor curve and immediately felt better throttle response. Next I selected the most aggressive curve, BANG! even better response. Lastly, I hooked a vacuum hose from the 750 Holley to the MAP sensor on the Crane distributor and throttle reponse and now mileage (highway) improved. The Crane unit is not a stand-a-lone, you have to use a Multiple spark capacitive discharge ignition. I kept w/Crane and used their HI-6 w/ built-in rev limitor, again dial adjustable. Pro-Street V-8 S-10.

I know a lot of guys are running MSDs and w/the boxes. However, I really like my DUI; my dads friend uses them on his stock car and I just got one for my SB 409 I built for my '71 . Plus all you have to buy is the distributor and you dont have to pay extra for the box and they will perform just like having one. DUI will custom curve the distributor to your motor and you can buy a rev limiter from them to install on your distributor. Even if something goes wrong and you need to order a new cap or something from DUI the guy said you can put a stock HEI cap on and it will get you around till you can order the new one. Just my .02 though. Good luck

MSD just released a new digital billet dist with coil, rev limiter(5000-10,000rpm), and timing curves using a dial on the dist. It has 20 preset timing curves and uses a 3 point connection(tach, batt, ?).

http://www.msdignition.com/2005/images/8394-Dials.jpg http://www.msdignition.com/2005/images/8394-Vac.jpg

http://www.msdignition.com/2005/2005_4.htm

it's a little expensive mind you... $375 but not bad when you consider all it comes with.

Looks like a nice piece