Small block rebuild

Conversion to v8 means, mounts,trans,rearend. They put 8 1/4” rears behind 318’s but you probably dont have one. Spirited driving with a v8 and 7 1/4” will be short lived and can hurt the transmission when it breaks. What is your budget? If stock v8 is what you want find a 360 with a 727 attached and go over each and throw it in. Start looking for 8 3/4”.