Size battery for a 66 Bronco?

[Bemac100]

What size battery should I put in my 66 Bronco?

Thanks for the help I'm still a rookie at all this.

 

[Gas Pig]

The original size and brand form the factory was group 24 Autolite.

 

[DirtDonk]

Luckily for us, just about any size (normal size that is) can be made to fit in an EB. Group 34 is a common size nowadays, as long as you get one with enough CCA (cold-cranking amps) and RC (reserve capacity). In batteries, as long as it physically fits, and you can afford it, the bigger the numbers the better.
I forget what the original size category was, but any battery supplier will have that listing.

Generically speaking though, you want a battery with a CCA rating approximately double the size of your engine in cubic-inches. So for a 302, you want a battery with a cold-cranking amp rating of at least 600. A typical choice for a lot of us is something in the 800 CCA range. Again though, more is better. Just go by budget.

For reserve capacity, it seems a lot of batteries these days have at least 90 minutes. If you find one in your category with 100 minutes or above (120 is common in the good batteries), so much the better.
Reserve capacity is almost more important for a utility vehicle as it's the amount of it takes to drain the battery to a certain level, which would indicate how long you can run accessories with the engine off before you can't start the engine any longer (and get yourself home from that outing) and get to walk.

As a rule too, I always get a battery with the negative terminal on the fender side. That way, if it comes loose or bounces around or you get in an encounter with something stronger than your fender, you won't short out the system by having the metal touch the positive terminal. Or at least it makes it much harder. To this end, many of the size categories can be had with reversed terminal orientations.
I mention this in case your supplier's info listing calls for a battery with the positive terminal on the passenger, or fender side.

Hope that helped without muddying the waters too much.

Paul

 

[blubuckaroo]

If you happen to be replacing the cables too, you can go to a group 75. More standard CCA, a better fit, and side posts.

 

[Gas Pig]

If you looking for reproduction 66 battery cables. Marti Auto Works has them but also the 66 plug wires and fan/water pump belt too. Just in case you want to go back to original.