ok so i have a 79 z28 with the stock 350 sb engine and a 4 speed trans
and ive found a 454 bb engine and i am wondering what all i would have to swap out or get new or fabricate to switch engines? will a 454 big block bolt up to a transmission for a small block? and i will have to change the engine mounts and countless other things right?

 

It's not that complicated, and not that much to change really.
Bellhousings are the same, so it bolts right up. The 454 is exxternally balanced, so you need a flywheel for the 454 and not one from your 350. The motor mounts and engine mounts will work if you use small block engine mounts bolted to your 454. They fit perfect, but you should buy new polyurethane or Moroso solid mounts if the 454 makes more than around 450HP. Otherwise the small chevy mounts will work and hold up fine.
The radiator should be changed to the big one if it's not the longer version yet. You can look at the core support and see where it's stamped for the larger radiator, and then cut it out with a jigsaw before installing the larger one. Just move the bottom rubber supports to the outboard holes, then buy the longer top hold down and bolt it in place. Upper and lower hoses will fit if you mark them and cut the correct length off, or just buy hoses for a big block in a Camaro.
Exhausts are a drop in if you go with headers. Not sure about every brand, but often the cheaper headers that aren't the equal length tubes will fit much better, as they're built to be more compact than more spendy equal length headers. My Doug Thorley headers were a snap to install, and dropped right down from the top with no trouble. They were the cheapest back in 1975, but now they're spendy.
Watch out for the heater core outlets while setting the engine. They're close, but once it's in they are clear and easy to put hoses on. I did have to trim the fins on the back of my old Edelbrock valve covers, but stock covers clear wioth no issues at all.
I've done 5-6 of these swaps with friends, and it can be done in a day easily.
Hope this helps.

 

thank you so much that answered all of my questions
i think swapping engines will be alot easier than rebuilding my 350 and converting it into a 383 and i need a new flywheel so thats perfect idk about the radiator though those are pretty exspensive arent they? but i suppose an overheated engine is no good either

 

You can get a good radiator for under $200. Tons of them on Ebay. Check this:
http://shop.ebay.com/i.html?_nkw=197...ator&_osacat=0

 

wow that is cheap, thanks for the help