Do i need to have a driveshaft made or is there somewhere that makes one for 4th gens with the TH350?

 

If you run the long tail shaft, you can use a stock length driveshaft. Some of the sponsors offer aftermarket one though

 

how long is the tail shaft? if it is a 6in then you will need to have a driveshaft made. if it is the 9 inch then you will be able to use the stock drive shaft.

 

Well looks like im just to late. Yes the stock driveshaft will work as long as you have the 9" tailshaft.

 

still have yet to pick up a trans, what cars can i find the 9 inch tailshaft trans out of?

I have a running th350 out of an old 72 LeMans parts car I picked up, but its a BOP housing

 

Big cars like station wagons, etc.

They are very common in vans and trucks. Be sure you don't get a th350c which is a lock up th350. These came in early 80's vehicles.
You can use one, either convert it to non lock up with a non lock up pump, input and valve body mods. Or an expensive custom converter if you plan to go with a higher stall speed. Make sure it doesn't have the electrical connector in the pic attached.
Also going by my tape measure, the long th350 is 1/2" shorter than an LS1 4L60E FWIW.