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Auto conversion from 4 speed to Auto


avantir3
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I am looking into changing the 4 speed to Auto in my avanti. I need a list of parts to look for. I have nothing now.Does anyone have such a list?

Should I use a 700 or 200?

Should I use Chevy or Ford?

I have an R2 Stock horsepower.

thanks in advance

Roland

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I know of someone who converted an Avanti II from auto to 6-speed manual and got all the conversion parts from Jon Myers, so that would probably be the first place I would go for parts to do the reverse. Jon's son Michael also makes an excellent quality adapter to use a GM automatic on a Studebaker engine. I'm not aware of anyone who makes such an adapter for a Ford or other make transmission with the Stude engine.

As far as whether to use a 700R4 or 200R4, you'll find many opinions on that. Some say the 200R4 has a better spread of gears than the 700. I have a 700R4 in my '70 and I can say the first gear is very low and shifts into second almost immediately. It took some getting used to taking off without smoking the tires the first gear is so low. The 200 may not do that...but since I have no experience with it I can't say. A stock 700 is stronger than a stock 200 (not including special 200's used in Buick GS's), but 200's can be built to be equally strong...not a real issue. Any good transmission builder will be able to build either transmission to meet the specs of your engine...he'll need to know the rear axle ration, cam specs, horsepower, etc., to build it to match the engine and use the correct torque converter.

Some have said they had to modify the transmission tunnel with a 700R4 for clearance. I didn't have to do that but it was found that a new neutral safety switch/backup light assembly had to be fabricated as the original wouldn't clear the exhaust. I do have to add I had a 2 1/2" exhaust installed in place of the original 2" so that may have been the cause of that and not the transmission.

You will need a different driveshaft...consider an aluminum one to reduce rotating mass. It's a bit more expensive but worth it...better performance.

You'll also need a different shifter quadrant than the stock Studebaker one...it looks almost identical but is made for the PRD321 layout rather than the PRD21 the Stude version. Avanti II's used the new ones when Avanti Motors went with the overdrive automatic. If Jon Myers doesn't have those Nostalgic does.

Give Jon Myers a call...he can give you honest opinions and information on everything you need. When its all done you can certainly sell your 4speed to help offset some of the costs of the conversion.

Edited by Gunslinger
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I would go with the 200 because you won't have to cut the tunnel and you can run the stock exhaust pipes. Considering the value of a 4speed R2 as opposed to an automatic I would make sure that nothing is done that can't be reversed like cutting the tunnel for a 700.

You will need to get very creative with the TV cable attachment to the carb. Edelbock makes an adapter to work with their carbs but the Stude AFB has no provision for proper location of that adapter. There may be someone on the Stude Forum that has made an adapter and can send you a template. I also recommend either a TCI trans or a trans built with their constant pressure valve body. It will allow you some room for error on that TV linkage and the cable adjustment.

You will need to find automatic shifter and linkage. There's nowhere to mount aftermarket shifters so you need the Stude or ideally an Avanti II shifter and plate.

If you decide to move ahead contact me and I can tell you every pitfall and everything you will need.

Ernie

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