What Alternator?

I am looking at running a dual Alternator set up. I am looking at the Tige RZ2 as the boat it will go in. The engine is the Marine Power 5.7 340 HP engine.

2 questions-

1. Can you recommend a good quality Marine Alternator that puts out over 120 Amps?

2. What size footing do you think I will need?

Thanks for your help

I've never done one, but this local shop does a ton of them, but I think their just using two upgraded stock alt's (usually 90 amps) www.boatstereo.com

The one guy who's had alot of exp w/ HO alt's is grant @ soundillusions. Give them a call. I went the cheap route , and foundn] some 135 amp ($140/piece) alt's to have 2 burn up in a matter of months. From what I've lkearned you can take a 105 amp alt and get it to max out @ 135 amps using cheap parts and it's a crapshoot to see if it will last.To do it right basically take a 105 amp alt, gut it and have all Heavy Duty parts put it to get to a true 135 amp (but it will cost you , close to $400 ish)Bigger than 135 from what I've foudn out gets really expesive. Don't forget tha typically HO alt's will haev realtively low output at idle. And to see full output your going to need to be running in the neighborhood of 3500rpms. How often do you do that? Grant's Balmar charging system seems to be working well. you can get on his site and see pics of the install. that may be better than going with dual alts?

I have read all of Grant's Posts and did send him a PM and e-mail (no response yet). I am looking at the Balmar series 6 either the 120 or 150. But like you said they are expensive. I think the dual system with a regulator and good bank of batteries will still cost me well under $2K. I just didn't want to go the route of Grant and spend $3-5K for a charging system.

Thanks for the input on the 135 Amp alts are they the ones they sell on E-bay? I am looking to charge a bank of 6V Trojans AGM (400 Ah). If I am right the number is 20-40% of your banks Ah to determine the size of the Alt. That gives me a range from 80 Amps to 160 Amps. So I figure I would be in the middle at 120 Amps or on the high end at 150 Amps.

another option is to install a second 100 amp alternator..