I'm at my wits end with the stock distributor/Petronix III ignition module and Igniter III coil in my 69 GS400. It does some weird stuff some times when I'm trying to tune it, and I'm over-it. I think the stock distributor may be a little worn too. The car has about 98,000 miles on it. I've decided to just go ahead and upgrade the ignition system to MSD. I've already got the MSD cap & rotor, and 8.8mm wires on the car with the stock distributor. Here is what I'm looking at get: 8552 Ready to Run Distributor (for the vacuum advance) 6425 6AL Box 8223 Blaster 3 Coil 8213 Coil Bracket (to mount in the stock Buick location) I like the MSD distributor's ease of adjusting the timing curve. This 400 seems to like a lot of initial timing too, which I really can not give it with the stock distributor. My mind's pretty made up about this, but I'm posting this to get some feedback from the folks that know Buick performance best. Please let me know your thoughts. Thank you!
I have heard and read that here, that the generic ones were. I thought the the MSD branded one would probably be more reliable.
See if you can send your stock distributor to Dave Ray for a rebuild. Get the MSD trigger option. He will modify your distributor advance to typically 20* of mechanical advance, although you can request whatever you want.. Then just plug it into your MSD box. https://www.davessmallbodyheis.com/
Larry, that was my original plan. I contacted Dave back in the beginning of December about it and he said then, that until further notice, he was not taking in anything until he was fully recovered from that spider bite. I'll try him again and see how he's doing.
I went through 4 Ready To Run MSD's on my F100. Put on a Davis Unified and never looked back. I'd take Larrys advice!
MSD used to be a premium brand. But there were always hints of trouble, starting with the need for race cars to have two boxes on board, with a switch to choose one or the other--so when one spark-box failed, the driver could engage the other one. The coils got outsourced to Mexico, and then to China. Junk. And now, it's not just the coils that are Chinese garbage. Then they went through a phase where the internal parts of the distributor didn't get reasonable corrosion protection. Lots of brown, scaly distributor guts later, I guess they started treating the parts again. MSD has been bought and sold a few times. Now they're a Holley brand. I used to be a fan of MSD, despite a couple of spark-box failures. Not so much any more. I have several old boxes, some of which still work. The only one I have installed on a vehicle is one of the first-generation 6AL analog jobs. So far, so good (but the vehicle hasn't driven 20 miles in the last five years.)
When they went to the all digital 6al boxes we seen alot of issues, I have 4 or 5 fail b4 I couldveven get the cars fully together and back to the customers. I started using the higher end digital 6 boxes...6520... and have not yet had 1 fail. But needles to say I do carry a spare in my trailer. I have seen several 7 and 8 series boxes fail at the track.
This all sounds pretty discouraging. Maybe I'll just see if Dave can build me one of his full HEI small body distributors out of a 1112110 or the extra 1111335 that I have. I really appreciate the input from y'all, thank you!
It is sad, for sure, I have a pro billet in my car with no issues, I have it locked out now, but ran it on the pickup with 0 issues. Once I stopped giving customers to buy bottom dollar boxes the issues went away.
I have 2 MSD boxes on my wish list. The 6520 and the programmable 6530, which allows you to adjust total timing, and change the timing curve with a laptop/pc. Does anyone have any experience with the 6530 or know of anyone using it? Jim
I've never used the 6530 box...but I have used the msd software it is pretty easy to understand. You do need to remember that this software can not add timing over where you have the physical distributor set.........it can only pull it out. And to really use the software correctly the distributor needs to be locked so it isn't swinging or you will end up with an issue. You need to set your timing at say 35 or 40, and then always map the pull out amount. And you need to verify the software know you physical set timing. Then you need to verify the pull out amount is correct by setting up some basic maps to very when the box thinks its at say 20....its actually reads 20 on your light and dampner, same at 25, and 30. Don't assume
To add another experience, I also had a MSD 6AL analogue that failed when I was drag racing a Dodge some 15 years ago. It failed not for my fault - i.e. wrong wiring gauge, abuse, others. Luckily, I managed to buy another at the racetrack and finish the fun for the day but MSD for me never more... I cannot speculate the failure of others but having a "high end" MSD ignition module for a car that is driven once in a blue moon and a tally of failures one can see on different forums is simply not acceptable on my book. All of which brings the good and reliable GM HEI. Yes, it can be improved (and should be) for spinning past 5500RPM - essentially due to a combination of module current capacity delivery and matching up coil characteristics (which are typically NOT stated in actual technical terms but simply as "hot coil" or other BS). Have these two well matched and spark plugs properly gapped and it works solid and reliably. In summary, I think the proposition of buying a distributor from someone who "is in the known" is good. The MSD improved slightly the startup and idle stability in my experience but the benefit was small to what it cost. This was added to later reliability concerns, it which the MSD removal is not be just "pull the thing out and wire standard back to drive home" given the setup I had at the time. FWIW, I am of the opinion a good (i.e. correctly modified) GM HEI suffices for naturally aspirated "hot performance engines" that do not spin to past 6500rpm and/or with a supercharge combination. Cheers/Alex
I ran a cobbled together HEI in my 430. It is still in it. Never any issues with it. Running one of T/A's HEI's in the new engine. Gone 10.50/126. No ignition box, nothing, just the HEI. 40 or so runs so far no issues.
Thanks for all the good input! I cannot run a typical Buick HEI distributor due to the ram-air air cleaner. It won't clear the large cap HEI without modifications. Since it is in great condition, I'm not going to modify it. Still waiting to hear back from Dave Ray. I'm probably going to pick up a 1112110 distributor and have him convert it to one of his small body HEIs.
