Yeah, Kevin. The question of how thick are the cylnder walls and how much can I overbore is the reason I was asking about which block would be the best choice. I had heard that the later 292's don't have quite as thick a cylinder wall as the earlier engines. I'd heard that blocks like the ECZ blocks were used as both 292 bore, 3.75", and 312 bore, 3.80 inch.

I have two ECZ-C 312 blocks already, including one that's bored .060, and I was thinking that maybe that's the direction I should go, an ECZ-A 292 block that can be easily bored to 3.80 or more.

When I check the distance between the cylinders on the ECZ-C blocks (inserting a drill bit through the freeze plug holes to see what size drill fits between the cylinders) I find that a 1/4" drill will not fit and a 15/64" will fit. I did find that one of the blocks seemed to have a slightly tilted cylinder; the space was wider at the bottom than the top.

When I try the same test on the C2AE block, one side measures 15/64" but the other side measures 17/64 or more; a difference of more than .030", presumably that's .015 per side.

I had heard that the later C1AE and C2AE blocks can't be bored out as much as the ECZ blocks. But the advantage of going with the later block is that they are reported to have beefier main webs, and have main bolt holes drilled a little deeper. I'll have to do a side-by-side comparison tomorrow to see if I can tell the difference.

 

I have two late Yblocks, one came out of a 1960 galaxie and is in a 56 fairlane at present, the other is the C2AE original engine in a 63 ford unibody f100 pickup, and the lower ends on those are indeed better than that of 1959 and earlier, i wasn't aware of the main webs and bolt holes for the mains being drilled deeper, but do remember the oil slinging rear seal problems was 59 down to 55 right around in there.

It was told to me by teacher Danny Clabourne and owner of Moores garage when i went to vocational mechanic school, that pre 1960 Yblocks had two problems, crank saddles that were not straight, and flat spots on the crankshafts prior to 1960 due to the lathes used in that time, but then today, that could easily be fixed. It is true however that the late Yblock does not have the beefier upper end (cylinder, heads and rockers) that the earlier y's did. But i can say, i have had very good luck with both my late Y's. If you can get away with not having to bore that C2AE out anymore than 0.60 over, i think you'll have a great engine, in my case i got lucky and mine is only 0.20 over, imagine how long mine will last, it has at least two more bores left in it, provided i take care of it......Janet

 

Paul, measure the thread depth as well as the total depth of those holes. Ive been able to pick up a few extra threads on several blocks just by using a bottoming tap.
Obviously the original processes were far from rocket science and I wonder if the later blocks were just simply drilled & tapped deeper. There certainly is plenty of depth available in early blocks.

 

hi, the y-block racers say that 3.875 is about as far as you want to go on a y- block but they have been taken out more with a sonic check but not recommended.