Has anyone here had experience boring out the super thinwall 1982-1985 HO block? I was wondering how far you can go without worry assuming it can be bored out at all.
Have it checked (for core shift and wall thickness) my experiance is 20, 30, and 40 over are all usaly std. 60 over can be done on some, but it's a bad idea. You can have heat transfure issures (running hotter than normal), but the big thing is the cylnder wall stability. An out of round hole from flexing will cost you HP, engine life, and an increasing chance of a catastrophic falure. The moral of the story, bore it out a little as possible, if you have to take it over 30 get a new block, there are tons of them and you will be cheaper in the longrun and make more power (hell, a block from my local yard is like 50 bucks)
I called Ford Racing before I left work and they said in theory it should withstand a .030" overbore but he hesitated and said due to its grey iron thinwall casting, it might not even stand up to a .020" overbore. He said don't even attempt to overbore it without a sonic test first.