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I have a 1979 L82 three speed automatic. I have been thinking about repalcing it with a 700 r4 automatic. Has anyone else done this and what needs to be change to accomadate this exchange. Also GM produced this for many years, so what year is the best choice? Any and all advice is appreciated.
 

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I have the same exact setup. A good place to look is monstertrans.com. They have a heavy duty conversion kit for $1800. Other than that i believe all you need is the crossmember, which is about $325, shorten the driveshaft, and an adapter? for the carb? Dont quote me on the adapter though. I plan on ordering this kit this week so ill keep everyone updated on how it goes. I've only heard good things about doing this trans swap.
 

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i have the same exact setup. A good place to look is monstertrans.com. They have a heavy duty conversion kit for $1800. Other than that i believe all you need is the crossmember, which is about $325, shorten the driveshaft, and an adapter? For the carb? Dont quote me on the adapter though. I plan on ordering this kit this week so ill keep everyone updated on how it goes. I've only heard good things about doing this trans swap.
dont forget the shifter ( ?$130)
 

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Monster has a great conversion kit. http://monstertrans.com/store/categories/Conversion-Packages/ you will need to shorten driveshaft and replace or modify the existing crossmember .. carb brackets come in kit..if you plan to get a salvage trans, look for later models, the early 82-86 had smaller input shaft. A few of us have done this ,so if you need info, let us know..you will love the end result. Oh, one other thing, if you get a salvage trans, you will need to swap out the servo to a Hi-perf.Corvette type ,,Fairbanks has a good one for under $100
 

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no, yours will work.. if you want to access all 4 gears manually,then you need to convert the detent plate ..theres a kit for that at Ecklers, comes with new 4 position indicator etc.. but isn t mandatory
 

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And the shifter itself? Is there a certain kind that I would have to get?

I just left my shifter "as is". No big deal as when I put it into 3rd it just makes an additional shift around 50 mph. That way everything appears totally stock. I sure love that 30% overdrive. Instead of cruising at 2400 rpm (60 mph) it cruises at only 1600 rpm. I had to cut my bracket apart (the bracket on the pan rail) and reposition the cable mounting location. Also no big deal as I have a MIG welder. All in all the swap was pretty easy and well worth it.
 

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By the way, the most desirable TH700R4 is the '87 or later versions as they used an input shaft that was .100" larger in diameter. And they also had a few heavier duty parts. If you're pretty handy with wrenches they're fairly easy (and inexpensive) to overhaul. All you need is a Haynes automatic transmission manual and a couple of easily fabricated tools. For about $250 you can buy an overhaul kit that includes everything you need in the way of clutches and seals. And for a few hundred more dollars you can buy the additional parts needed to beef it up to handle 600 ft/lbs of torque. I used an aftermarket 3-4 clutch pack that contained 9 frictions and steels (about $60 if I recall) and then added Fairbanks servos for another $180. Altogether I spent about $775 (which included the overhaul kit).
 

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TH700R4 Swap

Every time I take my 454" 1971 out for a drive I thank God I made the swap when I did. As gasoline prices have now exceeded $4 per gallon the 30% savings I'm making really adds up quick. The TH700R4 swap is great for any small block but even better for a big block as they're so stinking fuel hungry. I'm going to Santa Barbara this Thursday (a 500 mile round trip) so I'll find out what kind of mileage it gets on the open road. Before I made the swap it was getting exactly 10 mpg and after the swap it was getting 13 mpg (stop-and-go daily driving). I'm expecting around 15 mpg.
 

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Every time I take my 454" 1971 out for a drive I thank God I made the swap when I did. As gasoline prices have now exceeded $4 per gallon the 30% savings I'm making really adds up quick. The TH700R4 swap is great for any small block but even better for a big block as they're so stinking fuel hungry. I'm going to Santa Barbara this Thursday (a 500 mile round trip) so I'll find out what kind of mileage it gets on the open road. Before I made the swap it was getting exactly 10 mpg and after the swap it was getting 13 mpg (stop-and-go daily driving). I'm expecting around 15 mpg.
I like your setup with the 4 speed automatic with the big block. How long did the swap take? A few hours or 6 months like some people that drag it out all over the web, good lord enough already with the picture threads of bolt loosening and tightening. Anyway back on topic.

How does it run with the 700r4? Can the new trans handle the power? Did you buy the trans new or did you get it from a salvage yard?

I am thinking on buying an egg crate early 70's vette hopefully with the 700r4 already installed. hint hint. Are you looking to unload your 71?:thumbsup3:
 

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I like your setup with the 4 speed automatic with the big block. How long did the swap take? A few hours or 6 months like some people that drag it out all over the web, good lord enough already with the picture threads of bolt loosening and tightening. Anyway back on topic.

How does it run with the 700r4? Can the new trans handle the power? Did you buy the trans new or did you get it from a salvage yard?

I am thinking on buying an egg crate early 70's vette hopefully with the 700r4 already installed. hint hint. Are you looking to unload your 71?:thumbsup3:

The swap only took me a day.

It runs fantastic as it easily cruises at 1600 rpm in overdrive.

It's built to handle 600 ft/lbs of torque.

I bought it from a wrecking yard then rebuilt it.

Not for sale.
 

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You sound like you know your way around a corvette. My crossfire is being a little cheeky. It seems to be running a little rough. Where should I look first?
 

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You sound like you know your way around a corvette. My crossfire is being a little cheeky. It seems to be running a little rough. Where should I look first?

"Cheeky"? Are you referring to face cheeks or butt cheeks? Face cheeks are fun to nuzzle with whereas butt cheeks aren't. But I have worked with some people who preferred the latter.
 
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