Here are some before and after pics of the stock 1bbl manifold that I modded.
Backstory, I wanted to retain the factory manifold but have it flow better for my turbo application. So I milled the factory 1bbl hole larger to fit the opening area of a Holley 2300 2bbl. Yes, to my surprise, there is a sleeve and cavities. At this point I had to fill the cavities, so out comes the JB Weld! I made some forms on the filled with JB Weld.
Milled:
I check it after around 500 miles or so, to see if the "fill" was maintaining shape and not deteriorating. It looked the same as the day I put it in. Since then, I ran over 2000 miles on it, before I swapped it for an Offy.
Current:
