How much will it cost to convert my manual transmission to automatic

[my51chevyrocks]

On my 51 Chevy Truck?

[tantrumpipeline]

that would depend on how, what tranny, column shift or floor shift auto, doing it yourself or paying a shop, type of rad you swap to etc, could be cheap or really expensive

[blackdiesel]

I changed one once, 800 rebiult tranny 200 floor shifter 50 to cut down driveshaft. your results may very.

[mr48chev]

There are lots of variables involved in doing this.

1. what engine do you have now?

2. are you intending to run the close driveline or switch to open drive?
This only applies if you have the original engine or a 235. With later engines it is far more prudent to swap rear ends.

If you had the stock engine and wanted to keep the stock driveline you would have to run a Hydromatic out of a 54 Pickup or maybe a powerglide out of a 53 or 54 car (and I don't know if that will fit) as they are about the only options. Both would make it a real slug with a stock 216. More so than it is now. Both can be expensive to repair as you are hitting the vintage transmission area.

If you have a V8, 230,250 or late 292 six then you can bolt on a powerglide, turbo 350, 400 or other trans that matches up with the engine. Then it is a straightforward trans and rear end swap.

[raycow]

Adding to mr48chev's post, there is one other option you might want to know about. You can get a commercial adapter plate that will allow you to bolt a modern automatic to a 216, 235, or 261.
http://www.stoveboltengineco.com/aca...?productid=168

Naturally, you would also have to change to open drive, replace the rear end, and convert to 12 volts (for the starter).

Please don't think that I am advocating this route, because you could install a 230, 250, or 292 for no more work or money than the adapter would involve, and I feel the later engine would be a better choice. However, I just wanted to make sure you were aware of what else was out there.

Ray

[mr48chev]

I did find the link to the trans mounted neutral safety switch I was thinking about.
http://www.ronfrancis.com/products.asp?dept=35

I would imagine that several sources sell a similar switch setup. That would probably be the simplest and easiest way out on the shifter/neutral switch thing.