I used the small block LH 890 & RH 930 thinking this would center line the motor in the frame compared to bb frame mounts. They won't line up for the steel motor mounts not even close . I changed the mounts to lh 307 and rh 69 bb frame mount.With the frame mounts and the headers loose and the trans mount loose I tighted the frame mounts & headers than went to bolt the trans down and the trans had moved on the cross member a inch or more towards the pass side. Are the 70 bb not in the centered same as the nova's and camaro's. the header are 21/8 hookers and are VERY tight against the frame on both sides.
Kim