If you are using adjustable lifters with a later cam, they hit the later valve cover, creating a tapping noise.
How are you going after the wiring and igntion matters of the last few months?
TusconHooligan had similar issues with vehicle smoking, common with Weber carbs. That, ad stalling on turns.The carbs sometimes come fromte supplier with 2000 Pinto or 2300 Lima 4 cyl emulsions tubes and sometimes that creates a white haze due to the postions of the holes in the tubes in the carb. You can change these to the recomended Holley Weber 5200 items used in the 171 cubic inch Capri, something like an F2, (not a DCOE F2, but a special discontined Ford item used on all 155 and 171 Capri 2600 and 2800's and Mustang II's with the 2800, perhaps some of the last Pinto 2.8's got it as well). They are around on 1974 to 1980 Ford 2.6 and 2.8 V6's which still have the stock 5200 series Holley weber 2-bbl on them. F50's, a very common and still listed stock 183 cubic inch British 183 cube and German 171 cube V6 engine emulsion tube, may also help.
One other thing. I admire your Classic Inlines dual snorkel intake. Are the K&N Filters the RF 1048 like this
http://www.knfilters.com/search/product ... od=rf-1048
They are a standard aftermarket Viper 8.4 set up
K&N Universal Filter - Round Cone Filter (RF-1048)
Universal Air Filter
Cone Filter
Metal Top
Base OD : 7.5in(191mm)
Flange Angle : 0 degrees
Flange Diameter : 6in(152mm)
Flange Length : 0.625in(16mm)
Flange Offset : 0in(0mm)in
Length : 6in(152mm)
Top OD : 4.5in(114mm)
I am doing an under scoop conversion for my 250 Fox, and your filters look like they will package on Kens 1970 250 L code Mustang as well