1 and 3 look like the same Greddy knock offs not sure on the other two. You really can't tell by looking at the pictures how well they do performance wise. They do look like shorter runners but I am guessing the insides of those things are aren't going to be that great and that is what matters. That is how those china ebays guys do it. Stuff looks ok on the outside but sucks on the inside.
There are lots of kits for DIY intake manis out there in this same price range. If you could weld or know someone that can that would be a much better option.
+s
1. Save weight by not having China cast junk made of old pop cans
2. Have the flange on the right side
3. Put some bells ends on the intake runners inside of the plenum.
4. Make the proper volume and runner length based on your motor's volume and aspiration type. (So if you motor is NA you could make the inside of the plenum asymmetrical rather than using a manifold that is designed for a turbo.)
Originally Posted by MN_SR20 wouldn't the flange still be pointing towards the firewall?
there is a guy that uses the stock flange and welds them specifically for FWD. ashtonsser uses one of them. I only see it pop up every now and then though.