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Discussion Starter · #1 ·
I have an opportunity to purchase a '75 Loadflite tranny with overdrive. It may not be a good tranny, but I'm interested to know if the OD will bolt up to my '77 B300 Maxivan with a 360 and 727. If it will, is it a workable combination? I've been driving this van since 1986 and just replaced the engine and tranny for the third time at almost 300,000. I've always felt an OD would improve it's mileage and performance. I have a place to work and equipment, so mounts and other minor changes would not be a problem.

Thanks

Jack
 

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Are you sure its an overdrive? Chrysler didn't start using overdrives till the late 80's, but there is a transmission called the A-345 or something like that that supposedly is an overdrive tranny. Only time i've ever heard of one being found was in an old school bus mounted behind a 413 or 361 industrial engine. If you found such a tranny that came from this application more then likely it is for a big block and your 360 is a small block.
 

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Discussion Starter · #3 ·
Yes, it is a for a big block, but all I'm interested in is the OD. My tranny is new. It came from a D600.
 

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I'm going to say no, but I don't know how the OD worked on those old trannies. On the newer trannies the OD unit bolts on but there is differences in the valve body and passages in the case. I just don't know about those old trannies. I just went and check it is a A-345 and according to Chiltons book they were used 74-76
 

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according to my FSM fourth gear is 1 to 1 ratio and therefore not an overdrive. the FSM is a '77. There is a 3.56 to 1 first gear, more or less a granny gear.
 

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Dodge78 said:
according to my FSM fourth gear is 1 to 1 ratio and therefore not an overdrive. the FSM is a '77. There is a 3.56 to 1 first gear, more or less a granny gear.
interesting
 

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A-345s are 4 speeds with direct high, used the compounder to get granny low, they were never used in pickups, the compounder is huge, much bigger than 518 even. motor homes and medium trucks got them. The A-500 A-518 compounder won't even bolt on a 727 case
http://www.pbase.com/image/27313740 here is side by side view of 727 and 518 cases. The 727 has nothing there where some of the 518 compounder mounting bolts are.
 

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ODs were fairly common on 50s and 60s stick shift cars, I think they were made by BW. There was old hot rod or the like article on adapting these behing a 727, perhaps it's one of those. That where the gear vendors deal morphed from, I'm sure.
 

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Discussion Starter · #9 ·
"ODs were fairly common on 50s and 60s stick shift cars,"

Indeed there were. I've owned a few myself. A friend also suggested I might be able to accomplish the same end with a 2 speed rear drive axle. I'd wonder here if I could find one with the right ratio and track width, wheel size etc. Seems an illogical direction, but...........??? A used Gear Vendors over/under would be ideal.......New is too, too expensive for me.
 

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I would try and pick up that 345 anyway. Someone may eventually want it and it might be worth something.
 

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That is definatly an A-345, no OD there.Trouble with 2 speed rear ends, they're huge and either have dayton centers or use 10 lug buds. I think Ford had a small 2speed briefly available in some cars but they're rare as hens teeth. I think you're prime candidate for 518 swap.
 
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