I have a, 305 carb, auto th350 3speed with overdrive. Looking for more gears, what will easily bolt up that will give me more gears?

 

The 350 doesn't have overdrive.

What do you have; a 350, or a trans with overdrive? Identify it properly first, and go from there.

http://www.bulkpart.com/Merchant2/me...General-Motors

Go here for easy pan identification pictures.

 

Uhhhh. It's a 3 speed with lockup? Deffinate 3 and something more that doesn't feel like full gear. From that like I think it's a 350c? Could be wrong

 

Your choices are a 700R4 or a 200-4R.

 

Sure; we all could.

No point in arguing back with us about your confusion and uncertainty.

When you looked at your pan and compared it to the ones on the page, what did it turn that you actually have?

 

Doesn't matter if it's a 350c, a 250c or a 200c.
The 200-4R swap allows retaining the current driveshaft, but requires custom mounting. The 700R-4 can be done with all stock parts, you just need to find a good donor car.

 

if its the stock 87 transmission, you've got a 700r4. someone could have replaced the transmission before you, in that case you need to check out the link provided to identify the which one you've got.

as for direct drop in, you're not going to find a 5 or 6 speed that'll work without a lot of fabbing and money

 

I'd lay 1000-to-1 odds that he has a 700.

But until he GOES OUT AND LOOKS, and then tells us WHAT'S ACTUALLY THERE, there probably isn't alot we can do to help him any further.