Rory, I never made a pass down a track with this engine, but I do have a G-Tech Pro that I used to make some checkout runs with on this combination. With drag radials and 3.89 gears, and an 11" converter, it ran 12.70 on the G-Tech in my Mach 1.
I did the shaker comparison thing on my 511" FE about a year ago on the dyno at R&R Performance. The shaker cost about 15 HP on that 700 HP engine without any air filter, and adding the air filter actually made it better, up to about a 13 HP loss. In the car though, at the track, I lost a tenth by taking the shaker off and just running the carb open.
I've never run a comparison test with and without the lifter valley pan.
Jay Brown
1968 Shelby GT 500 Convertible, all aluminum 489" 1030 HP Supercharged FE
1969 XL Convertible, 460
1969 R code Mach 1, 706 HP 511" all aluminum FE, 10.457 @ 127.47, 2005 Drag Week Winner, Naturally Aspirated Big Block
