I am nearing my 340 build and machinist didn't use my 90-degree adapter (well becasue I hadn't taken it to him yet). So now I'm debating on whether I shoud use the adapter at all.

Aside from header clearance, is there a reason for why these were installed on small block cars? Are they factory or add-ons? I will use TTI headers.

Years ago I read about modifying the passages on this adapter. Does anyone have these notes on mods?

thanks in advance!