OK I'm not quite there yet but soon I'm going to need a set of filters for my dual "GX" SU carb setup. I don't have the original filter box and I don't think it'll fit on a LHD car anyway so I'm looking for other alternatives.

K&N makes a couple of different options, there are cone shaped filters and flat round ones with different thickness available. Here's a pic of the round cylindrical ones. from www.aptfast.com. Any idea which would be best? Is larger basically better for more flow? The'yre all 6" diameter which I'm pretty sure will fit. What about cones vs. cylinders?

Also these can be used with stub stacks like these. Are these necessary? The also make aluminum caste one which are cheaper.

So any suggestions and alternatives would be appreciated. Thanks
Michael