Quick questions about car battery sizes and a Chevy

[Anthony]

I'm going to get a new battery for my 04 Blazer and need to know if a group 34/78 size battery will fit.  The one that's in there now is a group 75.  I've read some model batts are interchangeable but the 34/78 Deka Intimidator I'm looking at is a little bigger in overall size. 

[665ae]

You'll have to pull out your existing battery and measure the tray (if it sits in one.)  Also make sure the battery hold down will work with whatever battery your putting in.

The problem I see (going by physical size) is that the 34/78 is over an inch longer than a 75. 

[jzmtl]

As long it fits in your battery tray and have more CCA there's no problem.

[Splat]

I'm going to get a new battery for my 04 Blazer and need to know if a group 34/78 size battery will fit.  The one that's in there now is a group 75.  I've read some model batts are interchangeable but the 34/78 Deka Intimidator I'm looking at is a little bigger in overall size. 

The "group" is simply the size of the battery. It has nothing to do with power capacity. Just ensure you get the either the same amperage capacity as what you have now or more/bigger. Measure you battery housing and go from there.