MSD Ignition box

mike britt · 02-12-2023, 07:35 PM

Can you get away with running a 6AL or do you have to have a 7AL. This is a 350 TPI 245/281 combo. Any advise would be appreciated.

Rory McNeil · 02-12-2023, 11:32 PM

I have had the same MSD 6T ignition box in my low 10-high 9 second bracket car for over 30 years, with zero issues. And I used a MSD 6AL in my 85 Mustang Stocker, but have never used a 7 series box, so I can`t say if a 7AL may potentially be any better. Certainly didn`t notice any downfalls with the 6 series.

427FE · 02-13-2023, 08:10 AM

Do you have it already?

Henrys Toy · 02-13-2023, 09:26 AM

Quote:

Originally Posted by mike britt

Can you get away with running a 6AL or do you have to have a 7AL. This is a 350 TPI 245/281 combo. Any advise would be appreciated.

Good morning to all,
Yes you can certainly use an MSD 6AL box, the 7AL " might " be slightly better in overall performance, but the 6 box will work. Over the years I've found the 6 series boxes to be the most reliable. That's what I've found, good luck with your racing season.

Respectfully,
Henry Kunz 1534 H/SA

Craig Porter · 02-13-2023, 09:36 AM

I bought a bracket car from a friend of mine two years ago and it had a digital 6 plus in it and worked great . I completely rewired the car last year and put a 7 AL box in it that I had and it didn’t run any different .

4543 · 02-13-2023, 09:41 AM

Mike I have a Digital 6 in the Corvette. Works fine. How’s the car doing? Mike McMahan

mike britt · 02-13-2023, 09:44 AM

I have a 7 AL2 in it now but I am going to replace it because I think it has a problem. At 6300 it acts like it's on a rev limiter and I allready replaced the distributer and wires so it's next.

PozQB14 · 02-13-2023, 10:06 AM

Hey Mike, what kind of shifter do you have? A few years ago, I had a similiar problem and it was my turbo action line lock button that wasn't fully disengaging. I had to push on the wires to ensure the little red button was fully out.

M120 · 02-13-2023, 02:05 PM

I replaced a 7AL2 with a 6AL between rounds after having the car shutdown on return road. Before it shut off the tach was jumping all over the place and would barely run.
I was racing an index class using weight to run the index. I didn't change weight after replacing with 6AL and ran exactly the same ET.
This was with a ZZ4 engine making around 380 hp . 11 second Chevelle

Adger Smith · 02-14-2023, 04:48 AM

Make sure your coil matches the box you are using.
Chart:
https://www.holley.com/brands/msd/pr...gnition_coils/
There is also a difference in some of the distributor pick ups and boxes.
I think it is analog vs digital. ran into a couple of customers with match up issues a few years ago.
Make sure they are compatible.

02-12-2023, 07:35 PM	#1
mike britt Member Join Date: Mar 2013 Location: Italy, Texas Posts: 169 Likes: 346 Liked 61 Times in 29 Posts	MSD Ignition box Can you get away with running a 6AL or do you have to have a 7AL. This is a 350 TPI 245/281 combo. Any advise would be appreciated.

02-12-2023, 11:32 PM	#2
Rory McNeil VIP Member Join Date: Jun 2007 Location: from Vancouver BC Canada, now in Nova Scotia Posts: 1,291 Likes: 292 Liked 1,052 Times in 287 Posts	Re: MSD Ignition box I have had the same MSD 6T ignition box in my low 10-high 9 second bracket car for over 30 years, with zero issues. And I used a MSD 6AL in my 85 Mustang Stocker, but have never used a 7 series box, so I can`t say if a 7AL may potentially be any better. Certainly didn`t notice any downfalls with the 6 series. __________________ NHRA 6390 STK M/S 85 Mustang

02-13-2023, 08:10 AM	#3
427FE Member Join Date: Sep 2016 Location: Monroe Twsp, NJ Posts: 191 Likes: 260 Liked 346 Times in 78 Posts	Re: MSD Ignition box Do you have it already? __________________ Pat Clemente #1427 B/S

02-13-2023, 09:36 AM	#5
Craig Porter Junior Member Join Date: May 2021 Posts: 45 Likes: 0 Liked 97 Times in 25 Posts	Re: MSD Ignition box I bought a bracket car from a friend of mine two years ago and it had a digital 6 plus in it and worked great . I completely rewired the car last year and put a 7 AL box in it that I had and it didn’t run any different .

02-13-2023, 09:41 AM	#6
4543 Senior Member Join Date: Apr 2005 Location: Texas Posts: 635 Likes: 56 Liked 621 Times in 136 Posts	Re: MSD Ignition box Mike I have a Digital 6 in the Corvette. Works fine. How’s the car doing? Mike McMahan

02-13-2023, 09:44 AM	#7
mike britt Member Join Date: Mar 2013 Location: Italy, Texas Posts: 169 Likes: 346 Liked 61 Times in 29 Posts	Re: MSD Ignition box I have a 7 AL2 in it now but I am going to replace it because I think it has a problem. At 6300 it acts like it's on a rev limiter and I allready replaced the distributer and wires so it's next.

02-13-2023, 10:06 AM	#8
PozQB14 Member Join Date: Jun 2015 Location: Youngsville, NC Posts: 129 Likes: 24 Liked 42 Times in 17 Posts	Re: MSD Ignition box Hey Mike, what kind of shifter do you have? A few years ago, I had a similiar problem and it was my turbo action line lock button that wasn't fully disengaging. I had to push on the wires to ensure the little red button was fully out.

02-13-2023, 02:05 PM	#9
M120 Junior Member Join Date: Apr 2012 Location: Atco, NJ Posts: 32 Likes: 19 Liked 22 Times in 12 Posts	Re: MSD Ignition box I replaced a 7AL2 with a 6AL between rounds after having the car shutdown on return road. Before it shut off the tach was jumping all over the place and would barely run. I was racing an index class using weight to run the index. I didn't change weight after replacing with 6AL and ran exactly the same ET. This was with a ZZ4 engine making around 380 hp . 11 second Chevelle

02-14-2023, 04:48 AM	#10
Adger Smith VIP Member Join Date: Dec 2001 Location: Texarkana Ark/TX Posts: 2,446 Likes: 575 Liked 880 Times in 311 Posts	Re: MSD Ignition box Make sure your coil matches the box you are using. Chart: https://www.holley.com/brands/msd/pr...gnition_coils/ There is also a difference in some of the distributor pick ups and boxes. I think it is analog vs digital. ran into a couple of customers with match up issues a few years ago. Make sure they are compatible. __________________ Adger Smith (Former SS)