340 Vs 360

And also
340 main journal is 2.50
360 is 2.81
Both 2.125
340 Floating pin
360 pressed
Same main cap, just opened .150 more cap side as well as saddle side to accommodate the 360's 2.81 journal
I think most 360 cyl walls are around .250 thick. +/- .060..but there are porosity issues along with erosion that cause weak spot that will do and sometimes are already cracked/veined from as cast. They are some of the late 70's blocks. 1978 for instance.
My fav 340 'I'll take any' but the best imo were the 1970-71 blocks.
70-73 cast 360 are desirable as they have been know to more than not have thicker cyl walls. They also use a smaller diameter thrust bearing. Early 360 thrust bearing will work in a any 360 late block but will not in late to early do to the thrust bearings register is cut to fit.
Check all 340's for oil feed misalignment and or hole diameter...they are known to be offset from the bearing oil hole and too small a feed passage to the main saddle=oil starvation if not addressed.
Heads, best are either 'for both 340/360' the 894/915, 974/596, 308/346, magnum 95-97 heads. The others that are good are oddities like the partial 915 '77-79' the 576 which was a performance head, and the rt.
You can make good about all of them, but imo..those are the best 360/340 iron heads.