I am changing out the original 350 in my 69 RS project for a 427. The front springs that were in the car (it is totally dissasembled for the frame off)are new. If I swap in a big block with aluminum heads, rad, intake and headers, will I be able to use the small block springs? I am using the original M-21. All other front end parts are being replaced as well. I am just waiting for the front clip, rad cradle, wheelwells, A-arms to be powdercoated and I will be ready to start putting it back together.