87 MGM Battery

[87GrandMarq]

My 87 mgm has been sitting with a dead battery at my parents house for a bit. Life got in the way and then I had surgery so I’ve been out of commission with that but I’m looking to replace the battery soon. The last time I replaced it I got a group 56 from Walmart but now I’m having a hard time finding them. I might be able to get one from a batteries plus or other specialty store but that’s kind of a pia if that’s my only option. What group size are you guys running on your 87ish boxes? I’d like to keep using the stock hold down and have it fit in the tray if I can.

[friskyfrankie]

My 87 mgm has been sitting with a dead battery at my parents house for a bit. Life got in the way and then I had surgery so I’ve been out of commission with that but I’m looking to replace the battery soon. The last time I replaced it I got a group 56 from Walmart but now I’m having a hard time finding them. I might be able to get one from a batteries plus or other specialty store but that’s kind of a pia if that’s my only option. What group size are you guys running on your 87ish boxes? I’d like to keep using the stock hold down and have it fit in the tray if I can.

You could "Dremel" the part of the tray that makes the smaller battery fit and stuff a Size 65 in. Works great and not that much work!

[kishy]

Most brands seem to have dropped group 56 a number of years ago. It's a difficult battery to get my hands on locally, so I started just running 65s in everything with (as friskyfrankie noted) some alterations to the battery tray area.

A full proper conversion would involve taking the inner fender liner and some other pieces off an 89-91 as those came with group 65 from new, but you can get away with just the hold-down bracket and some rotary tool cutting.

I will note that AutoZone still carries a group 56.

[Tiggie]

I had a Group 27F in my 82. It was in the car when I bought it and seemed to fit fine.
I believe most people trim the battery tray and run the commonly available Group 65.

[87GrandMarq]

I’m going to take a look at it later and see what needs to be done. It had a 65 in it when I bought it but the po didn’t trim anything so it sat wonky and wasn’t held down. That’s probably going to be the way I go since it’s a common size. Thanks.

[Kodachrome Wolf]

65s don’t sit well with that odd bump on a pre-‘88 liner. A 64 is what I run in my ‘87, but I think those are hard to find. I have a 24R (sometimes also seen as 24F) in the ‘79, and that fits about as well as a 64 and goes under the battery hold down too. 24R batteries are usually available about anywhere.

[friskyfrankie]

65s don’t sit well with that odd bump on a pre-‘88 liner. A 64 is what I run in my ‘87, but I think those are hard to find. I have a 24R (sometimes also seen as 24F) in the ‘79, and that fits about as well as a 64 and goes under the battery hold down too. 24R batteries are usually available about anywhere.

I cut out the "hump" in the battery tray and a "65" sits just fine (on an "87) with no other alterations.

[sly]

The battery tray was pretty much rusted to nothing in the 88 I had so I had to add a universal tray with J bolt tie down and used a 24R for that setup. Worked great.