Help! we have grafted a Chevy 350-small block and turbo 350-trans from a 5-thousand pound camper. Can it be used in a 1973 vega? Do we need to change the torque converter? this one is 10-inches.
Any help appreciated!  

The V8 Vega swap has been done thousands of times. A 350/350 combo was probably the most popular variant of it back in the days when you could still find a rust-free Vega with a dead stock mill.

A 10-inch converter sounds fairly small for stock in a "5000 pound" camper ("11-"12 would be more expected). But a converter that small ought to have a moderately high stall speed without being so loose that it wastes too much gas on the street.

You won't need a lot of converter stall speed with a stock 350 in a light car such as a Vega, unless you add a lot of cam and other hop-up parts that shift the torque curve higher.  

i am assuming you are talking about the factory vega converter??weren't they like 9 inches??