Carb jetting or HardBlok in the water jackets ? Compression test may show if any excess ring friction in the bores is causing heat and wear and checking a magnetic drain plug for iron particles or even an oil analysis can find other friction/wear/heat sources.
I've used the Holley blue gaskets and reused them many times with jet changes.
I did have an issue a while back where the initial installation was fine but subsequent re-used caused a leak, apparently after the gasket was initially compressed. Something in, on or around the carb was keeping the...
If I remember correctly, Champion plugs with a "C" on the end (i.e.: N-10YC - more search options) were an upgrade from the originals and had a copper core, or something like that.
May be related but I read somewhere that cranks 360 cranks with CFD cast into them were stronger than the ones with AAWJ and that CFD represented a GM foundry!
As mentioned about Champion plugs, lower # = lower heat range. Some other brands follow that pattern while others are lower # = higher heat range. Gotta check your brand.
FWIW N9Y were originally for high compression 340s and N10Y were for 426 Hemis. (I believe Champion 61 & lower were...
Just in case.....it's also a good idea to hone with deck plates to simulate any bore distortion that the head bolts may cause when assembled. Some people go so far as to use the same head gasket that goes into final assembly as well as bolt on a head or deck plate on the other side and...
Agreed! I've gotten at least a tenth better performance going from a 3310 750 vacuum secondary to a 4779 double pumper after spending time tuning both on the same combo.