Auto transmission
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Teching In
Joined: Jan 2014
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From: Madison WI
Auto transmission I have a 1946 chevy coupe with a 396 & 700r4. Would like to upgrade engine with a ls motor. Will the stock flexplate on the ls motor bolt up to the 700r4 or does it have to be modified. Thanks for any help. Pat
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From: Ann Arbor, MI
Since no one else has answered your question, let me take a shot at it even though I have no experience with a 700r4.
I suspect the 700r4 would require the same "mods" as a pre '98 4L60E:
1. You will need a spacer on the flexplate to extend the crank's pilot hole to reach the 700r4 converter. It is about $50 plus $10 for 6 longer bolts.
2. The holes in the stock LS1 flexplate need to be elongated about 1/8" to match the 700r4 converter. You should do this on the bench.
I suspect the 700r4 would require the same "mods" as a pre '98 4L60E:
1. You will need a spacer on the flexplate to extend the crank's pilot hole to reach the 700r4 converter. It is about $50 plus $10 for 6 longer bolts.
2. The holes in the stock LS1 flexplate need to be elongated about 1/8" to match the 700r4 converter. You should do this on the bench.
I would get a dual bolt pattern flex plate that way you can run both if you ever decided to swap and run a 4L65E and its the same $$$. Also if you plan on keeping the 700r4 behind a lsx engine, unless you use a carburetor you will also need to figure out how to run the TV CAble ad correctly or you will just burn the transmission up. Unless you go reverse full manual valvebody then you dont need to worry about havin the tv cable. But the standard flex plate that accepts the 700rd/4L60/4L60E converter isnt the same unfortunately.
Last edited by Docrocket1967; Mar 14, 2014 at 02:39 PM.
