Alright here is the basics. ... it has 350 with 350 turbo needs back floor pans some dash work and maybe some other rust touch up other than that I drove it a solid hour no problems shifting good and just cruising well I need any help with doing the interior any help will be much much appreciated thank you

Would post pictures but I dunno how yet

 

Welcome to the forum! What's the plan beyond fixing the sheet metal?

 

Just redo interior grab another 350 block make me a 383 stroker with a 5 speed put in

 

Sounds pretty simple. If you go to a 5 speed, it should be a T56 type if you're putting it behind a 383 stroker motor.

 

Any tips on redoing the floor pans

 

If you mean total replacement, then yes. Lay the new pans on the floor, and mark around them with chalk or grease pencil. Then cut your hole about 1" smaller than the outline. Set the pans back in again, and check the fit. Then mark the pan from the bottom side with a marker, and check that. Once you're sure they're correct, cut the new pan down to fit the hole. Be careful to not get it too small. Cutting, and checking, or grinding more off where needed is easier than adding or filling if you cut too much. Make sure you get some butt clamps to put along the joints, so welding will be easier, and not have to fight it while you're tacking them.
These butt clamps from Harbor Freight work great, and I keep a couple sets on my cart all the time:
8 Piece Butt Welding Clamps

Also be sure to tack at several locations, but don't run beads! Too much heat will warp sheet metal, so the idea is to jump around, and check as you go. Once it's well tacked, you can remove the clamps, and then keep moving around until all the joint is done. Then just grind it, and it's done. Use a coarse grinding disc, as it keeps the heat down too.

Here's a video that's pretty interesting for patch panels: