New to drag racing. Need advice.

Are those super stock springs?
If so, can you find the part number on them?
The rear shocks, are they drag shocks? The more adjustable they are the better you can dial them in.
Your tortion bars, how thick are they? Skinnier bars up front allowmorenand quicker weight transfer to the rear. Front shocks should also be adjustable.

I would also jump on board about the welding done from the previous owner. Re do that nicely. Same with the subframe connectors. Double check and reweld.

If you move away from the S/S springs, CalTracs would be very good to use in there place with there split mono spring. CalTrac also has there own line of shocks that work well.

You can also use a Slide a Link on the rear of the leaf springs. They replace the shackles for a plate to weld in the frame and there is a bolt that goes into the spring and through the sliding link. It helps free up the spring movement. It maybe one step more than needed but this is what I would do and consider.

Once the above is done, going further is more money and racey. That will be your call to move away from basic race prepped parts that should work very well.