1979 Corvette Battery - Group Size

[Paul L.]

The AC Delco battery in my former 1979 Corvette is giving up the ghost after eight years. It is a Group 75. I 'phoned the local GM dealer and they say the replacement should be a Group 70. Is this correct? What is the difference between 70 and 75?

[Dick W.]

Re: 1979 Corvette Battery - Group Size

Group 70 is 3/4" shorter in length. Height and width are the same. As long as CCA are at least equal you should have no problem

[Joe L.]

Re: 1979 Corvette Battery - Group Size

Paul-----

First of all, I don't think that a Group 75 is a correct battery size for a 1979 Corvette. I can see where it will work, but I don't think that it's correct. A group 75 battery was used on C4 Corvettes due to the rather limited "battery box" size. However, it was not originally used on a 1979 and I don't think that it was a Delco-catalogued SERVICE replacement battery, either.

Currently, the Group 70 battery is the current Delco-catalogued SERVICE replacement. However, you can use a Group 78 battery, too. I'm surprised that the Group 78 is not the current Delco-catalogued replacement; it was for many years. Delco may be trying to "phase out" the group 78 battery in favor of the group 70 which will fit more applications. "One-size-fits-all" is a "good thing" in the world of automotive aftermarket parts. Plus, newer GM cars now have gone back to top terminal batteries and no other major automobile manufacturer ever went to side terminal batteries. So, the world of side terminal batteries is going to be getting smaller by the year.

[Paul L.]

Re: 1979 Corvette Battery - Group Size

Thanks for those replies. I will have a peek at the 70 tomorrow - the dealer says they have not ordered one for years - and see if it fits in the 1979 box. If not, it goes back.

[Joe L.]

Re: 1979 Corvette Battery - Group Size

Paul------

I don't think that there will be any problem, at all, with fitment. It will fit perfectly. The question is will it be the largest (and, most powerful) battery that you can fit in the compartment.

As Dick mentioned, the "footprint" of the group 70 and group 78 is the same. The difference is in height. That extra "height" means more power generating capability. The more, the better in the case of batteries.

[Tom S.]

Re: 1979 Corvette Battery - Group Size

The 75's are readily available in Florida. I just bought one last week for my 88. Tom

[Paul L.]

Re: 1979 Corvette Battery - Group Size

The Group 70 fits fine as Joe said. It is 550CCA with a six-year warranty. Thanks for the comments.