bought both the synchronizer and air/fuel ratio guage, both are excellent both my EH with a very warm 179 with twin Stonbergs is running like a dream and purrs like a kitten but give ithe boot and she roars like a lion. As for the 302 Cleveland powered 47 Ford Pilot with the 500CFM 4 barrel on it is running like a clock smmoth and much more power. Excellant products.