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			#1  
			
			
			
			
			
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|  Gear ratio changes 
			
			Hey guys, I was wondering if someone could give me some much needed & appreciated advise. I've been searching for an outdrive for my 77 V-20 with a 165 hp in-line six for some time now. I found a local guy that has a 1986 17' Renken with a blown inline 4 banger. It does have an Alpha l outdrive. According to the charts I'm looking at his gear ratio should be 1.94 The gear ratio for my Wellcraft in-line 6 is 1.62. What will be the most noticeable change in performance? Loss of top end speed but quicker out of the hole? Is it advisable to chage the gear ratio that much? I'm been floundering on this issue for awhile mainly because I've been out of work for some time & my Doc(s) are saying disability & I'm too stubborn to file for it and money is real tight, but I can get this this Renken with a single axel trailer complete for $640 with titles!!! I know this boat will sell quick, but I was the first person to contact the guy when it hit Craigslist today. I'm just concerned about the difference in gear ratios and how will it affect performance. Thanks for all advise. | 
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			#2  
			
			
			
			
			
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			you can make it work, I've seen worse, you'lll have to change props(go up in pitch)but keep in mind you can buy a new complete drive, ratio of you're choice from stern drive engineering for around $1200
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			#3  
			
			
			
			
			
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			Most 165hp used 1:65:1 an 86 4 cylinder alpha one would be 1:98:1.  I think you are looking at gen 2 charts or the sei stuff. Yeah you could make it work but  you would be better off finding a 470 drive  they were geared 1:84:1. Amazing what a prop can do but mercruiser geared em they way they did for a reason. Brian | 
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			#4  
			
			
			
			
			
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			You didn't mention the size of the 4 banger, but in case it's a 470/3.7L four cylinder motor, they run a 1.84 ratio.
		 
				__________________ 1983 V20 Cuddy, 3.7L/165hp Mercruiser Fishing out of Portsmouth NH | 
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			#5  
			
			
			
			
			
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			It's a 2.5L 4 banger. The guy thinks it just a blown head gasket. It is not a wise idea or does it really make a noticable performance differance on my motor. Rear ends are changed all the time in cars like a 3.73 if you are looking to cruz or a 4.10 to get to the end of the 1/4 mile first. If it were your boat, would you do it if you could get the Renken, trailer, & titles for $640? The only other good option I have is an identical outdrive as mine, used with trim pump arms and complete outdrive with gimbal housing for $500. I have a brand new water pump for the lower unit already. | 
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