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| Transmissions and Rear Ends Three on the tree or four in the floor? Shift it all here. | 
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			My 62 3/4 ton truck has .456 rear gears and I would like to slow the motor down some at highway speeds. It has a 3 speed (SM318)transmission , I have access to a SM319 transmission with overdrive and was wondering if anyone has done a similar swap and if it was worth it. I AM going to keep my column shifter and am not interested in floor shift conversions. Thanks for any input. Dave
		 
		
		
		
		
		
		
		
		
	
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			Dave:  
		
		
		
		
		
		
		
		
	
	I have the seven bolt side cover 3 speed with overdrive transmission. My tranny has synchronized first gear. I am running 3.54 rear end. Results in about 2000 rpm's at 60mph. I think it was one of the best upgrades I made. Parts are getting a bit hard to source, but so far I haven't needed anything since I installed it a few years ago. Hardest parts are electric solenoid and governor switch. My vote would be to go for it. I think it would cut your rpm's about 30% in overdrive. Hope this helps. Manuals for tranny can be found online for free. Let me know if you are interested. Regards Steve New Orleans  | 
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			Steve, Thank You for the info! Think I will go ahead and put in the overdrive.  Dave
		 
		
		
		
		
		
		
		
		
	
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