Originally Posted by Sniper
Originally Posted by cudaman1969
My 63 engine had 426 TMPHC iirr but really there’s no difference in any block from HC to non HC, just what’s put inside


T stood for 1963
MP was maximum performance (max wedge I believe)
HC was the high compression version, 13.5 vs 11.5 I believe

At least that is what I recall from playing around with them back in the 80's.

You are correct about the actual block differences though, none.

Thanks, you nailed it. Wish I had it back, sold the whole car in 78 for $2800 lol