cleaning up the slant six head

vnted, I'm all for "usin' what ya got", If it will be on the street more that just track duty. Will you be doing a full rebuild ? If not and just rings & bearings the 170 is a zero deck block where the 225 the pistons are in the hole quite a bit. I ran a 67 Dart 4 door with a stock bottom end 225,500 afb,intake and header, mild cam,automatic and head work. The car was in full street trim,open header, 4.30 gears.Best pass was 15.40 in Tulsa OK. I think you can be easily knockin' on the 14's door with your 64. Your goin' "Gasser" so you can loose quite a few pounds removing unnecessary items.
Look up 64 Dart 2 door sedan in member restorations. We are just about finished and will be trying it out at the track next month to see what it will do.