The blocks ARE the same between HP and non-HP....it was the added goodies that got the HP stamp on the block. If you're doing a complete rebuild, you're going to changed those parts anyway.
Exactly my point cudamark, It's like trying to pull teeth to get a diffenative answer from the people that are supposed to know, what constitutes all the internal goodies that merits the HP stamp. Is it 915 heads with the 1.74" exhaust valve (the head they called the Magnum), valve springs with inner dampeners, which cam out of 3 possibles is it, which carburator, dual point ignition, exhaust manifolds or just all of the above. Maybe the people that did know are looking up seeing dirt instead of blue sky go rest their souls.:read2:
