Dont waist your money an a olds 307 unless your looking just for dependabilty which you can get out of your 231. Now if you found an older model sbc307 that would make a great build.THEW said:I have a 1980 Regal with a 3.8. I'm wondering what transmission I have and what V8s, if any, it is compatible with. Also, how much work is involved in a 307 swap as opposed to a 305 or 350?