I had a problem with gas smell before I changed the head. The fuel pump was hooked up wrong The return was open and the line was hooked to the vent! IDFK. I fixed it and the smell got less but still hung around especially on hot days. I noticed there was gas pooled in the Intake when I rebuilt the carb after doing the timing and balancer belts a few months ago. It got great mileage after that. When I put the rebuilt head on there was no gas smell for the first few days but today while I was flushing the radiator I noticed the smell and the exhaust is very rich smelling. The fuel gauge has gone down form full to less than 3/4 in under 100 miles. that's as bad as it was before I did the timing belt. I got the head from Ivan in St Louis. I'm new at this but I seem to have some talent with proper instructions. What could it be and how might I go about fixing this? Even a carbed motor should not smell like gas as much as this does.