your best bet would be to change the oil pan. I put a 69/70 kadette block in my 73 but I used the 73 steel oil pan and drilled a hole in the block on the starter side......there is a place for it and even a pilot hole on mine. The hole needs to be 13mm and you will need the filler tube and probably the oil pickup tube from the later model.
or it seems I've heard there is an aluminum oil pan....maybe off a Manta??.... that has an dipstick hole on the starter side that will fit and not require drilling thru the block. I think this oil pan even has cooling fins on it. I never could find one in time.
or it seems I've heard there is an aluminum oil pan....maybe off a Manta??.... that has an dipstick hole on the starter side that will fit and not require drilling thru the block. I think this oil pan even has cooling fins on it. I never could find one in time.