Does anyone have experience using 59 degree heads on a 48 degree block? I've heard it can be done but what is involved and is it worth it? All 48 degree R3 blocks are siamese bore and I have heard that cooling system mods are needed to keep them cool enough for street/strip use, I read how to build big inch small block mopars and he says to drill .125" holes between the cylinders to allow coolant flow but doesn't that defeat the purpose of a siamese bore? 4.600-4.22-.125=.255 is that bad? I suppose its better than individual .125" walls on a non siamese cylinder. The reason I ask is that I have a scat forged 416 rotating assembly and am tired of looking for a decent 340 block for $500 or less to replace the one I have that needs lifter bushing. The R3 block seems like a better investment, thanks in advance for your replies.
