Which battery for 390?

[Leadfoot 4]

Hi I just bought a non-running 69 Mach 390 4v garage find. (I'll post details and photos later.) It hasn't been driven in 7+ yrs, so I am going through the whole process of getting it ready to fire.

 

The Mach came w/o a battery. What is the correct size for the 390 4V. 24F or 27F? It is my understanding correct that a modern 24F has the same cranking power as the 27F from the 60's? The brand, size, or style does not matter to me at this time. I am more interested in having the max cranking power to turn over that big block. Thanks.

[ashleesmach1 28]

in Batteries the bigger you go the better. 

[Brian Conway 264]

The battery tray size may be the deciding factor ?  This one is in a 428 car and holds the group 27 battery.  brian

[jholmes217 65]

My car had an Optima Red in it when I bought it in 2010.  I have no idea how old it was, but it pooped out on me this summer.  I bought a Duralast at Autozone that had more cranking power than the Optima Yellow (not as much as the red,) and was almost 1/2 the price.  On top of that, it was on sale, and Autozne has a 10% military discount.

[LindenBruce 27]

Well, battery technology has come a long way since the 60's. So batteries today are better than they were back then for sure.  The "F" designator is for Ford applications.  Ford swapped the terminal positions on the battery to better fit their vehicle back in the day.  You can use any say group 27 battery, but you will need to buy a longer cable that's all.

 

Given you are turning over a big block, I would go with as many CCA's as you can get.  B.

[barnett468 418]

if it wont turn over with a 24, it won't turn over with a 27 and something else is wrong . if it as high compression, a gear reduction starter is the way to go and a plain 650 or more cca group 24.

[Leadfoot 4]

Thanks for the info, I really appreciate it.

[RPM 1,190]

in Batteries the bigger you go the better. 

 

So you're saying size matters???  :)

 

Hi I just bought a non-running 69 Mach 390 4v garage find. (I'll post details and photos later.) It hasn't been driven in 7+ yrs, so I am going through the whole process of getting it ready to fire.

 

The Mach came w/o a battery. What is the correct size for the 390 4V. 24F or 27F? It is my understanding correct that a modern 24F has the same cranking power as the 27F from the 60's? The brand, size, or style does not matter to me at this time. I am more interested in having the max cranking power to turn over that big block. Thanks.

 

Well, it's been two weeks and we A.D.D. folks are getting impatient :)  We (I) also like to get a bit of info on how you obtained the car, what part of the world you call home and such. Welcome aboard mate.

 

[1969_Mach1 333]

I use an Optima red top battery.  I rarely drive the car so I also keep a Bettery Tender connected to it.  But the battery is about 10 years old and still seems fine.  At the time Optima was the only option for a battery without a liquid in it.  There are others now.  I chose it because I didn't want the small ammounts of acid seeping out from the vents or around the battery posts that typically happen with lead/acid batteries.  The biggest thing that shortens battery life is discharging and recharging.  From what I was taught during GM training courses, every time a battery goes through a discharge cycle some sulfur deposits on the plates.  Recharging it removes some of the sulfur but not all.  Eventually enough surface area of the plates are covered with sulfur and the battery will not work anymore.  If you don't drive the car daily I suggest a Battery Tender or something like it.  Get the battery size that fits your car.  Either a group 24F or the larger group 27F on big block cars.  If your car takes a group 27F get the group 27F battery.