Re: 1976 johnson 85hp
Bombardier makes a complete exhaust block filler kit for their later V4 engines. 392000. It's about $ 172 and still available. Some things to check: your block may not be cast with the bosses to mount the filler blocks to, since these were designed for the 99.6 cubic inch block and yours is the 92.6 block. Attached is a picture of a 135 block with the exhaust stuffers installed. Just below the two stuffers, there is a casting bridge which should be removed. You can see the shiny mill cut. Not sure you'll get any gains that are worth your effort. Are you running the intake stuffers? Have you upgraded the carbs, reeds?