I'm with EMW on this one, can't hurt, either way. If you look at all the pix of where the stock roller blocks crack, then it makes alot more sense; majority of the time, the crack propogates from where the main cap bolts go up into the webbing-which is thru-tapped...then right up throught the cam journals, and into the lifter valley. If you look at the older (pre-'74) blocks, they all have blind tapped bolt holes in the mains as well as the deck, plus the architecture in the webbing is totally different. Instead of the meat of the webbing being shifted off to one side (if you took a cross-section of it, it would look like an "L") of the beam that runs under your main caps as in a new style block. The old blocks are centered in the beams...creating a "T" shape-much more structurally sound design. If you don't mind either using a flat tappet cam, running $400 lifters with a factory style roller, or having a small base circle cam with stock style roller lifters, then I'd say go with an old style block, and throw some milodon, or pro-gram engineering main caps on it, stud the mains-instead of bolts, and go from there. The only reason I'd say go with studs is that they transmit virtually no twisting distortion into the block (another cause of stress fatigue), and they typically have better clamping force than bolts. Besides people were running 10's on those blocks long before the FI 'stangs were a glimmer in Ford's eye. Also, you would be well served to go with a 28oz bottom end as opposed to the stock 50oz...less weight outside the block swinging around putting stresses on the front and/or rear main cap.
...just my 2 cents.
Any help on this subject would be much appreciated because I want to order one asap. Cheers!
