A block vs C block

[6667fan]

I picked up a CJ carb yesterday and the guy has a C block that I'm sniffing for a possible buy. He starts telling me that he would rather build off an A block because they are actually heavier and therefore stronger than a C block. Can anyone support this?

Thanks,
JB

[428kidd]

Not true on a whole. Some of the A blocks are thicker cylinders, and less core shift.  However that is not always the case and spotty info at best. Really no difference on a whole except dates and very few A blocks have the 3 web  mains.

[jayb]

When I bought the 19 428 irrigation engine blocks from the shop in Nebraska, there were 3 "C" scratch and 1 "A" scratch blocks in the mix.  I didn't see any differences in the sonic tests between the A and C scratch blocks, and in fact I think the C scratch blocks looked a little better.