Made by Scott Drake, these Tri-Y Headers resemble traditional Tri- Y's in appearance, with subtle changes to enhance fit and performance! 16 Gauge Tubes are CNC mandrel bent, then carefully installed in our precision engineered welding jig for a perfect fit, and precision welded by a master craftsmen. Many hours have been invested on making these fit and perform. They have been fitted on multiple applications and we find them superior to previous suppliers. These fit both automatic and manual transmissions with the more common 157 Tooth small bell housing, along with extra clearance for starter, mounting flange bolts can easily be accessed and they clear Shock Towers.* Provides full articulation of steering assembly without interference. Note: Power Steering cars require Drop Down Bracket see below. Cars with the larger Bellhousing for 164 Tooth Flywheel will need to dimple header and possibly remove a minimal amount of material on Bellhousing as well for proper clearance. We have also shortened the collector tubes to improve floor pan clearance. Over forty years of Mustang modifications have resulted in endless configurations and combinations, but we believe this product offers the best overall fit and appearance so far. Although one product will never fit every application possible, we at Scott Drake believe in a "Constant Improvement" atmosphere and welcome your feedback, so that future mod's can be considered. All Headers include extra thick 5/16 inch flanges to prevent warping which are precision ground. Metal composite flange gaskets, 1 ½ inch Primaries, 1 ¾ inch Secondary's and 2 1/2 inch Collectors. Includes Reducer Cones which taper to 2 inches with gaskets and all necessary mounting hardware. 304 Stainless Steel Our stainless steel version features Polished Stainless construction, including the 5/16 inch mounting flange, most manufacturers call their headers all stainless, but actually use regular steel which is nickel plated steel to reduce costs. Ours are all 100% Stainless Steel right down to the flange mounting bolts. The best money can buy, no corners have been cut. *Note: 64-65 V8 Engine Mounts sit the engine approximately 1/4" lower than the 66 and up mounts. Although unlikely, it may be required to shim your engine up especially if mounts are older and have partially collapsed to gain more shock tower clearance. This can be done simply with some washers.