I found the thread about the ridges in the plenum floor, http://forums.y-blocksforever.com/Topic133974.aspx

More info in May - June 2018, Vol 25, No. 3, Issue 146 of Y-Block Magazine.


Lawrenceville, GA

😉👌

Mummert's intake may have an edge in performance vs the Blue Thunder, however the Blue is more original looking, which may matter to some & it has  under carb heat crossover, that Mummert's doesn't..  Another route for some, particularly if originality is important, may be to find a good condition '57- ECZ-B intake (at a reasonabale price) & if you have a Die Grinder, small metal cutters, epoxy & course long strips of sandpaper belt to remove the sharp corners into the runners & some time & patience, it can be modified to work better than stock. I believe that route has been described here some & also in Y-Block magazine  some time  ago. I did one about a year or more ago. It takes about 8-10 hours over a couple of days to do it.. Note; that the heat tube in the crossover is often rusted out in old intakes & will need replacement if you plan to use a heat style choke feed... 
N.B.- the article on porting a "B" intake, by Doug Thrasher, is in Issue #140, May-June 2017..   


Paul