Battery, what mod.#
Race Director
Joined: Sep 2004
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From: Redsox, Pats, Celts & Bruins !!! Redsox Nation !!!
St. Jude Donor '06-'07-'08-'09-'10-'11-'12
Originally Posted by Blue Lion
According to Optima's webpage, you need the 75/35. You may need an adapter to have it fit--I've heard varying stories on this. My 2000 didn't need an adapter.
Le Mans Master
Joined: Jun 2004
Posts: 6,269
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From: Dallas Texas
St. Jude Donor '06-'07-'09-'10
I got a 34/78 from Sears in my 2K Vert and it has 980 cranking amps normal and 800 cold. It can sit for 10 days to 2 weeks with no problem. You need the GM adaptor clamp that comes with it to tie it down. 
Team Owner
Joined: Sep 2001
Posts: 23,283
Likes: 906
From: Lake Elsinore, CA
Either the 34/78 or the 75/35 will work in the C5. The former is older but slightly more powerful. You don't need any sort of adapter. I run the 75/35 and got a new clamp block from Optima for a better grip but the stock one was working fine before I got that. Optima sent me the block free of charge.
Here's my 75/35 with the stock clamp block.
You can see the clamp block Optima sent me in this pic with my 75/35. It conforms to the Red Top's shape better than the stock block.
Here's a 34/78
Here's my 75/35 with the stock clamp block.
You can see the clamp block Optima sent me in this pic with my 75/35. It conforms to the Red Top's shape better than the stock block.
Here's a 34/78
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I put a 74/38 model in mine. Has worked fine for over three years.
Thread Starter
Racer
Joined: Nov 2004
Posts: 288
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Originally Posted by Patches
Either the 34/78 or the 75/35 will work in the C5. The former is older but slightly more powerful. You don't need any sort of adapter. I run the 75/35 and got a new clamp block from Optima for a better grip but the stock one was working fine before I got that. Optima sent me the block free of charge.
Here's my 75/35 with the stock clamp block.
You can see the clamp block Optima sent me in this pic with my 75/35. It conforms to the Red Top's shape better than the stock block.
Here's a 34/78
Here's my 75/35 with the stock clamp block.
You can see the clamp block Optima sent me in this pic with my 75/35. It conforms to the Red Top's shape better than the stock block.
Here's a 34/78
