I just broke-in my 440-6 on a test stand using new, but 10yr old repro carbs out of the box. Stealth heads, lunati 60303, stock manifolds, TTI 2.5. Only change to the carbs was #65 jets instead of #61 stock.
However, intake leak gradually degraded idle quality. Used paper gaskets on valley pan, but didn't seal paper to head/intake surface. Used permatex black to seal second time around. Running good. Just installed engine in 70RR couple days ago.
