There is an aluminum 4 barrel intake manifold available for Y-blocks. There is an aluminum front cover available for Y-blocks. There are aluminum heads in the works for Y-blocks. Now all we need is a big-bore cross-bolted engine block for the Y-block. A 4.15 bore would yield 372 cubic inches with the 312 stock stroke of 3.44. A 372 CID Y-block would put out about 300 HP at 4500 RPM. With a 700 CFM carb the 372 could rev up to 7000 RPM , and with cross-bolted mains , and the right con rods and pistons , it could probably take 7000 RPM with no sweat.

 

Will the cylinder spacing allow 4.15" bores? Even just a 4.00" bore would be a nice improvement.

And wouldn't a 372 make 320hp at 4500 rpm if it can produce 372ft/lbs of torque?

Too bad there isn't a slick way of reworking a 292 to get bigger bores.

 

Paul,the Y-block bore spacing is 4.38,which would leave 0.23 between the bores with a 4.15 bore. My figure of 300 HP was a conservative round number - your figure of 320 HP is more like it. You could perhaps grind out the entire cylinder of a 292 and have sleves furnace brazed into place - its rather expensive - and if you wanted the 3.44 312 stroke you would have to have a 312 crank ground down on the main journals - the 312 crank has larger mains than the 272-292.