Okay, I'm working on a 1973 240Z which has been sitting for, oh, 10 years or so before I bought it. I am shopping for batteries, and low and behold I realized something rather odd. My car has side post battery cables (as best I can tell, I've never owned or worked on a car with side post battery cables before), and as best as I can tell, the Z came with more conventional battery cables.

My questions on the matter boil down to

-Is my conclusion correct?

-What size battery do I really need?

-Should I switch the battery cables and get a top-post battery, or just buy a side post battery? I don't know if there is any performance, durability, or monetary reason to go with either option.

-Should I wish to replace the battery cables, what's the difficulty rating? It looks deceptively simple, which is usually when some tiny PITA part breaks and costs you an extra $100.

I have the original battery hold down bracket (original as far as I can tell), and it has had some cutting on the side done to accommodate a side post battery, is my assumption.

Use the biggest battery that will fit.No such thing as "too big"(amp rating).FInd a shop that makes battery cables from welding cable(0 or00).You'll have no more starting issues.

I would wager that you had a top mount battery from the beginning. It is an easy swap. You will need new positive and negative cables, which should not cost that much. You can get them from black dragon or MSA.

The installation is easy, and if you take your time and replace one cable at a time - one fitting at a time, you will be just fine! IF you have any questions at all, just ask.

I put a group 24F in my 77. I would have came with a group 24. The "F" has the positive post on the opposite side. My logic, after buring a hole in my hood when the battery shifted, is that the positive post would set out from under the inspection cover and if the battery ever moved again, it wouldn't arc and burn another hole.

Cables and batteries can be purchased at NAPA, Orielly's, etc. Nothing special about them at all unless you are going for a spot on restoration.

Their is no performance advantage to side post if you like them and they meet your needs keep them. Optima batteries and several other brands have top and side mounts that way you can switch if you want later down the road

The original size battery was of the Group 24/24F top post type. If the side post cables are in good condition, a Group 74 (side post) is the same size as the 24/24F battery and should fit fine.

Use the biggest battery that will fit.No such thing as "too big"(amp rating).FInd a shop that makes battery cables from welding cable(0 or00).You'll have no more starting issues.

No starting issues so far yet.... but no starting either, seeing as I don't have a battery what fits in the car

Thanks everybody for the suggestions! All the battery groupings are greek to me, knowing things like F for the mirrored terminal layout is a cool bit of knowledge. I'm not going for a spot-on restoration, but cheap and easy original things are fine in my book, I bought the car from a fellow who was considering pulling the fully working original engine to replace it with a small block chevy, not my cup of tea.

I had a shop make up some battery cables a couple years ago. On one, the post connector cracked, and on the other, the square bolt head spun.

The odd thing about the battery is that I went to NTB to get one, and the one the guy brough to the counter was obviously too small! WTH?

Edited May 1, 201014 yr by TomoHawk