transmisson queston
 

I have a power glide in my 68 LWB and I am looking to put a th350 or 400 in it. how difficult is that swap and what would i need to buy besides the obvious transmisson?

Re: transmisson queston
 

Those PGs are worth their weight in gold to racers....I've seen them go for $1000 or more in good shape.

I am not sure about driveshaft length or crossmember, but I think both have to be changed out.

Re: transmisson queston
 

It's been a long time since I went to a TH400 from the Powerglide.
I think (not for sure) you'll need a different flexplate. You'll need shifter linkage for a TH400. The driveshaft will depend on whether you get a long or short output shaft TH400. The kickdown switch on the TH400 is electric and can mount on the carb or on the gas pedal.
The PG crossmember can be used, but I think it has to be moved. There are already holes there though, so you don't have to drill any.
Torque converter for a TH400.
Like I said, it's been a long time ago, so there is probably more I didn't think of.
TH350; I don't know anything about. Never had one.

If you're going to get rid of the PG, sell it to a dirt-track racer. Like Gray Ghost said, they're worth some good money to those guys.