I Put a 650 cfm Edlebrock new in box off ebay for cheap on dads 1970 318. with an Edlebrock intake I bought for $20 from a friend. Dad said it never ran so good, even from new when he bought it. Has quite a bore job (not sure if it is .40, .68. Or .80 seeemed like a lot when I picked up the motor in 1995. This last summer I replaced the junk home made exhuast with a huge kink oved the oil filter with a set of Headman headers for about $160. It did have decked heads as well, and I think a mild cam. It has a 3 speed manual geared very low, and will consistantly chirp the tires at 60mph going from 2nd to 3rd gear at 5500 rpms. Car is my daily driver in the summer, and has many trips to 6k since the rebuild in 1995,and uses no oil between changes. Hope this helps, been told the old ones made more power, but I don't know for sure?