318/8 Speed Swap
The drag links are cast iron, and they really should be iron or steel given the type of load they can take and the section area you need.
Honestly you'd be a lot better with something like the ToddRon crossmember and cutting the floor. If you lower it, everything will be jacked up, bump steer, tie rod angles, pitman and idler arms, driveshaft angle, ground clearance, exhaust, etc. An aftermarket K-frame with front steer might be the only thing that could help.
But honestly if you have 220V welder and some skills with it, you just cut the floor and make a new center crossmember IMO. You'll be done about 20x faster and everything will work right. Been 2 years on mine and its perfect, also you basically forget about the floor being cut.